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International Correspondence Schools 





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72 1 950 



R 19Y6 L 

Copyright, 1902. by International Textbook Company. 

Entered at Stationers' Hall. L^mdon. 

I'umps: Ci>pyriK:ht, 1908, by International TEXTBix>k' Company. Entered at 
Stationers' jhlall. London. 

Elevators: Copyright, 19(W, by INTERNATIONAL Textblhjk Company. Entered 
at .Stationers' Hall, Ix>ndon. 

Steam Heajin^: Copyright, 1H07. by THE Colliery Engineer Company. Copy- 
right, WJB. by International Textbook Company. 

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All rights reserved. 

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Pumps. Section, Page. 

General Introduction 34 1 

Steam Pumps 34 5 

Rotary Pumps 34 32 

Centrifugal Pumps 34 35 

Power Pumps 34 37 

Mine Pumps 34 39 

Displacement Pumps 34 57 

Water Ends of Reciprocating Pumps 34 64 

Riedler Pumps . 34 ./•... 70 

Details of Pump Water Ends .... 35'v-'j* 1 

Air Chambers 85 *• ' 13 

, • ••• •• 

Pump Foundations ''US ./., ; 19 

Piping y*A\ 3^. **• .••V^'^ 

Pump Management 
Defects in Pumps 
Calculations Relating 

The D'Jty of Steam Pumps --^36:- 16 

Size of Suction and Delivery Pipes . . 3t} 25 

Selection of Purtps ■ 36 29 


General Description of Elevators ... 37 1 

Hand-Power Elevators 37 19 

Belt Elevators 37 27 

Steam Elevators 37 42 

Indirect-Connected Electric Elevators . 38 1 

• • • 


'v**. ^& *• ,-•-22. 

']'-. . .-:]^y\:r>'.^<;:,;^'36 

to Pumps > . '/• ^/y 1 


Elevators — Continued, Sec turn. Page, 

Direct-Connected Electric Elevators .38 11 

Elektron Elevators 38 15 

See Electric Elevators 38 27 

Otis Electric Elevators 38 34 

Elevators Operated by Alternating Cur- 
rent 38 46 

Electric Elevators with Magnet Control 38 52 

Automatic Electric Elevators .... 38 75 

Sprague-Pratt Screw Elevator ... 38 86 

Eraser Differential Elevator .... 38 92 

Introduction 39 1 

Plunger Elevators 39 2 

Piston Elevators 39 9 

Pumps, Tanks, Pipes, and Fixtures . . 39 32 
Operation and Maintenance of Hydraulic- 
Elevator Plants 39 41 

Car Safeties 40 1 

Accessories 40 16 

Indicators and Signals 40 25 

Escalators 40 30 



. ln{to(fucl*on 41 1 

^/^•4lr^\Wl^)JJ8 ot''lI<^''iting by Steam .... 41 3 

".•■^!vi^^^V**«t^"^^*'^'^-^^^^ Steam Distribution . 41 4 

' ' VVsifghy C^iMp^v-Sjc^tems .\ :.%:/•• .\ . * . \ ,: 4t : : ,•; 9 

Ex&ii)pt Vhfl Viwruum Sy/t^fiis^ '.■ . '•'' ^V- '-' ' 24 

Distrlift ^ystom '!>;. :..':: j4I 29 

-tem Details . , :'\'\ .'-41 31 

» • * • # 

;ing Plant .v .. f .v. .•-'.. 41 ■ 49 

lONS. Seetion. 




1 37 

a 38 


Examination Questions — Continued, Section, 

Elevators, Part 3 39 

Elevators, Part 4 40 

Steam Heating 41 

Answers to Examination Questions. Section. 

Pumps, Part 1 34 

Pumps, Part 2 35 

Pumps, Part 3 30 

Elevators, Part 1 37 

Elevators, Part 2 38 

Elevators, Part 3 39 

Elevators, Part 4 40 

Steam Heating 41 

» - • 

• ' 

• • • • ••-•• V • — 


(PART 1.) 



1. Pamps are machines for lifting or conveying fluids, 
and when not otherwise specified the word is generally 
understood to mean machines for lifting and conveying 


2. Water is a liquid composed of 1 part of oxygen and 
2 parts of hydrogen. The weight of a cubic foot at its max- 
imum density (39.2° F.) is G2.425 pounds; at 32° F., or the 
freezing point, water weighs G2.4 pounds per cubic foot, and 
at 212° F., or the boiling p<jint, water weighs 59.7 poiinds 
per cubic foot. Obviously pumping machinery can only 
handle water between the limits of the freezing and boiling 
points. Water is almost non-compressible; its compressi- 
bility is about .0000014 of its volume under a pressure of 
15 pounds per square inch, and it decreases with an increase 
oC temperature ; for practical purposes it may be considered 
«f iaoompressible. 


& ■ Pomps are frequently so located that the water must 
"into the pump cylinder by atmospheric pressur<! on th<- 
of the water external to the suction pipe; that is, by 

8 34 

of oopf rii^bt, see paj^e immediately following; the title pa;;e 



the action of the pump a vacuum of more or less perfection J 
is produced in the pump chamber. If the end of the suction | 
pipe, which is the pipe connecting the pump chamber v 
the water, is submerged, the excess of pressure on the ! 
face of the water outside of the suction pipe will cause the I 
water to rise in the suction pipe until the pressure due to the I 
weight of the column equals the pressure of the atmosphere. I 


4, The pressure of the atmosphere is constantly chan- 
ging. For practical purposes the pressure at sea level is 
lakcn as :ici inches of mercury, or 14.7 pounds pressure per 
Sfjuarc inch. Since a pressure of 1 pound per square inch is 
equal to that exerted by a column of water 2.30!t feet high, 
ihc theoretical height that water can be raised by a perfect 
vacuum at sea level will be U.7 X 2.309= 33.94 feet. Since 
the atmospheric jiressure becomes less as the altituds 
increases, it follows that the greater the altitude, the less the 
theoretical and practical lift by atmospheric pressure will 
be. To find the theoretical height in feet to which water 
can he lifted at any altitude, multiply the barometric read- 
ing in inches by 1.133. 
A. For water holding foreign substances in suspension, 
: for other liquids, the theoretical lift can be found by 
IVN tlieorctical height to which water can be lifted 
almosphcnc pressure, as shown by the 
^specific gravity of the liquid. 


■acuiim cannot be obtained on account J 

irfections, air contained in the water, and | 

»atcr itself, the actual height to which it J 

■only .82 of the theoretical height.y 

ly for pure water, 
of pum|)3 located at the bottom of deepfl 
leter Hill plainly show a -greater pres 





the bottom than at the surface, and hence a greater sue 
tion lift is possible at the bottom. 


8. Pumping hot water is a difficult problem and has 
positive limitations in the direction of lift and temperature. 
Whenever possible, the pump should be so arranged that 
the hot water will flow to it. The following table shows the 
theoretical possibilities at 30 inches barometric pressure: 



Suction Lift. 













In actual practice it is not possible to lift water at all 
whose temperature exceeds 180°. The reason hot water 
cannot be lifted is on account of the increased pressure of 
the vapor at the higher temperatures. Pumps required to 
handle hot water should be provided with suitable valves of 
vulcanized rubber for the lower temperatures and metal for 
the higher temperatures. Soft rubber valves are unsuited 
for handling hot water. 


9. Having considered the limit of lift by suction, the 
limit of height to which water or any other liquid can be 
forced will be discussed now. This height is not affected by 

4 PUMPS. § 34 

the atmospheric pressure and is only limited by the power 
available for forcing the liquid and the strength of the 
pump and the pipe connections. 


10. Before proceeding to give an account of some of the 
best and most modern types of pumps, let us consider for a 
moment what is required to be done in order that large 
volumes of water may be raised in the best possible manner 
and with the best possible economy. Among the first things 
that a practical engineer should know and among the last 
things he should forget is that in handling water within 
pipes he has a fluid which, while it is flexible to the greatest 
extent and is susceptible to the influence of power or force 
of greater or less intensity, and while it may be drawn from 
below and raised to a height above, and while it bends itself 
to the will of the engineer, will still refuse to do some things 
and which all the complicated appliances of the engineer 
have as yet failed to compel it to do. When enclosed within 
chambers and pipes to an extent that fills them, it will not 
[)ermit the introduction of any more without bursting them. 
When enclosed within long lines of pipes, it will not sud- 
denly start into motion or.when in motion suddenly come to 
rest without shocks or strains more or less disastrous. 


1 1. Almost the first application of steam was to pumps 
used for raising water out of mines, and as these pumps had 
I)reviously been entirely operated by horses, a basis of com- 
parison was established by rating the power of the steam 
engine by the number of horses it displaced at these mine 
pumps. To enumerate even briefly the various machines 
for pumping water that have been developed in the past, 
many of which are famous, would be quite impossible for 
lark of space, and a description of their peculiar and promi- 
nent characteristics wmild he equally so, especially as they 
are only of historic interest. Conditions have so changed 

§ 34 PUMPS. 6 

as regards steam pressure, speed, and problems of manufac- 
ture and competition that out of the great mass of pump 
designs, some of which were excellent in many points, have 
been developed standard forms of pumps particularly adapted 
to each and every service. 


12. Pumps may be classified in a number of different 
ways, as according to their principle of operation, their 
general form, the power used to drive them, the methods of 
applying the power, the special class of work to which they 
are applied, etc. There being no universally accepted classi- 
fication, no attempt will be made here to classify pumps, 
but the different forms of pumps described will be given the 
name by which they are most generally known. 



13« Steam pumps are pumps in which the moving force 
is steam, which is applied to the movement of water with- 
out the intervention of belting or gear-wheels. Steam 
pumps are divided into two general classes known, respect- 
ively, as direct-acting and fiyivheel-pattcrn pumps. 



14. General Description. — The type of pump by far the 
most numerous is the direet-actingr pump, by Which is 
meant a steam-driven pump in which there are no revolving 
parts, such as shafts, cranks, and flywheels, or pumps in 
which the pressure of the steam in the steam cylinder is 

6 PUMPS. § 34 

transferred to the piston or plunger in the pump in a direct 
line and through the use of a continuous rod or connection. 
In pumps of this construction the moving parts have no 
weight greater than that required to produce sufficient 
strength in such parts for the work they are expected to 
perform ; as there is, consequently, no opportunity to store 
up power in one part of the stroke to be given out at 
another, it is impossible to cut off steam in the cylinder 
during any part of the stroke. The uniform and steady 
action of the direct-acting steam pump is dependent alone 
on the use of a steady, uniform pressure of steam through- 
out the entire stroke of the piston against a steady, uniform 
resistance of water pressure in the pump, the difference 
between the power exerted in the steam cylinders over the 
resistance in the pump governing the rate of speed at which 
the piston or plunger of the pump w^ill move. The length 
of the stroke of the steam piston within these pumps is 
limited and controlled by the admission, release, and com- 
pression of the steam in the cylinder. 

15. Devolopment. — The direct-acting steam pump was 
invented by Henry R. Worthington in the year 1840 and was 
patented in 1S41. A few years later Mr. Worthington 
developed and brought out what is now known as the 
duplex dirert-.'irling steam pump. The objection to the sin- 
gle <iirt'(*l-artin}^ pump was the fact that the action of the 
j)iiinp i)lun.ij:('r or piston was an intermittent one; that is, the 
(olmnn of water was started into motion at the beginning of 
« .i< h 4 \y .kc and ( ;nn«' t< » a stand at the end of each stroke, thus 
ii'.t -.iil\ iii.ikiii- t he llow of the water irreji^iilar, but also sub- 
1< < I 111- 1 Ih |)iiin|) and the (H)nueetinj2^ i)ipes and their joints to 
s< \«i<-.iiid <>ti<n sci'i( HIS St rains. 

H5. Duplex IMiiiips. -In tlie main, the construction of 
th( ^icam and water ends of tlie duplex pump differs but 
sli-hily from that <»f the sin^lt! direct-ac^tini:^ pump, but the 
niei hani^ni that operates tht^ steam valves is different and 
th<' ( ffci i ..11 the water eohnnn is very different. The prin- 
ei{)le ujton whi( h the (hiplex punij) operates is this: Two 

§ 34 PUMPS. 7 

pumps of similar construction are placed side by side ; a lever 
attached to the piston rod of each pump connects to the slide 
valve of the opposite steam cylinder, and thus the movement 
of each steam piston, instead of operating its own steam 
valve, as in the single pump, operates the slide valve of the 
opposite cylinder. The effect of this arrangement is that as 
the piston or plunger of one pump arrives at or near the end 
of its stroke, the plunger or piston of the other begins its 
movement, thus alternately taking up the load of the water 
column and producing a regular, steady, onward flow of 
water without the unusual strains induced by such a column 
of water when suddenly arrested or started in motion. 

17. Advantagres of Direct-Acting Pumps. — The 

direct-acting machine is the simplest form of pump yet 
devised ; its action most nearly harmonizes with the laws con- 
trolling the action of water, and in event of a conflict, the 
direct-acting pump will yield to the superior force of the 
water without serious resistance. The direct-acting pump 
b6ing not only the simplest but most universally used type of 
pump it will be taken up first. 

18. I>Isadvantagres of Direct- Acting Pumps. — To 

obtain perfection of steam pumps it is necessary to use the 
steam so that by cutting it off within the steam cylinders 
and by subsequent expansion in the same or other cylinders, 
its expansive force will be developed to the highest limit and 
to the most economical extent. When that is done we have 
accomplished all that with our present knowledge of the 
steam engine can be done in the steam cylinders. It is in 
this respect, however, that the direct-acting steam pump of 
the ordinary type is anything but economical, its design 
requiring the carrying of the full steam pressure throughout 
the whole stroke. This drawback prohibits its use in places 
where a high economy in the use of steam is imperative. By 
the use of a so-called high-duty attiichment, however, the 
ordinary direct-acting pump can be and is converted into a 
machine using steam expansively ; a fair degree of economy 
is also obtained by compounding the steam end. 


8 3*1 


19. The Knowles Valve Motion. — Fig. 1 shows the 
steam end of the Knowles steam pump with the arrangement 

of the valve gear. 

An auxiliary piston /> works in the steam chest and drives 
the main valve i'. This auxiliary, or chest pli^ton, as it is 
called, is driven backwards and forwards by the pressure of 
the steam, carrying with it the main valve, which in turn 
gives steam to the steam piston P and operates the pump. 
The main valve i> is a plain slide valve of the B form working 
on a flat seat. The chest piston has a rod A' to which is 
clamped an arm .S, the latter being connected to the rocker 
bar /"by a link /. The main piston rod carries an arm O, 
which is provided with a stud, or bolt, on which there is a 
friction roller. This roller moves back and forth under the 
curved rocker bar with the motion of the main piston rod and 
lifts the ends of the bar, thus giving the chest piston a slight 
rotary motion just at the end of the stroke of the main piston. 

>iston. ^^1 

§ 34 PUMPS. 9 

Each end of the chest piston is provided with a port o, shown 
in the right-hand end by the partial section, and the solid 
part of the steam chest has four ports a, b and a\ h\ which 
open into the space in which the chest piston moves. The 
ports a and a! connect with the live steam space in the steam 
chest and serve as steam ports, while b and b' connect with 
the exhaust. In the position shown in the figure, the main 
piston has jitst reached that point of its stroke where the 
roller has acted on the rocker bar to rotate the chest piston. 
This has brought the port o (in the right-hand end of the 
chest piston) into communication with the live steam, admit- 
ting the latter to the space at the right of the chest piston. 
This steam drives the chest piston to the left and it carries the 
main valve v with it, thus exhausting the steam from the 
right of the main piston and admitting live steam to the left. 
When the main piston, under the action of this steam, 
approaches the right end of the cylinder, the roller lifts the 
right end of the rocker bar, thus rotating the chest piston so 
as to bring the port o in connection with the exhaust port b 
and the port in the opposite end of the chest piston in con- 
nection with the steam port a! , This drives the chest piston 
and main valve to the right, allows the steam at the left of 
the main piston to exhaust, and admits live steam to the 
right of the main piston again. The chest piston, as it 
approaches either end of its chamber, covers the exhaust 
port at that end, thus confining enough of the exhaust steam 
to form a cushion to prevent it from striking the end of the 
steam chest. The main piston also covers the exhaust port 
before reaching the end of its stroke, as shown in the figure, 
so that it is cushioned by the exhaust and prevented from 
striking the cylinder head. Special passages are provided 
for admitting the steam required to move the piston far 
enough to uncover the main ports on the return stroke. The 
arm (Scarries a collar that slides over the chest piston rod, 
and in case the steam pressure is not sufficient to move the 
chest piston, this collar will strike collars, as //, and thus 
move the valve. (One of these collars is just behind the 
arm 5.) 

20. The Cameron Valve Nation.— In ibe Cameron 
pump sfauvn in Pig. i, which possesses the advantage of 


^ no onuide gearitq;, a is the Mca.m rvlinder, 
piaoKL, d tbe pistnci rod. / the steam cbest. / tbe cfaesi pis- 
ton, tbe rqrbt-itaikd end of which k shown in sectjoo. g tbe 
main elide valve, k tbe starting bar, ooaoected with a han- 
dle en the oatstde, t. t the rrvcrsing valves, h, i tbe bonnets 
over tbe reversii^-valve cbambers. and t. e are eihaust 
parts leading from tbe cikH fit the steam AeSL direct to tbe 
Bain -T**"**^ and are dosed by the reversing v^ves t, i. 
The aawa oi this valve motim is as fiJliiws; Tbe sfOCes 
ecbcstpastceyoommanicate vitb tbe Inrc- 
s of small botes, uoc c< vfaiii is diova 
i sectiaA vi /. By means of ibesc holes, 
I Uk ports e, c Icadii^ f rooi Ibem are kept 
im as long as the pons are corered by tbe 
In tbe position shown in the figmc, tbe 
■ ^finder tu the right of tbe pcston r is ta 
I the lire-steam spacK in the Stem 
• moTTQg to tbe left. When t stiftes 
> ibe valw i, ii fi>rres t to tbe left and 
Stbc Irit ''.:;n-i port ■-, thus alkwing the steam ax the 
tM|ias» ■ jt ■.brou^ tbeexhausi. Tlie sieam to the 
I expaiKb and drinrs / and with it the main 

§34 PUMPS. n 

valvL' ^ to the li^ft, thus reversing the acliua of the steam 
on c, which immediately begins l<i muve back towards the 
right. Live steam Js always acting on the piston /, so that 
as soon as f moves to the right, this steam pushes t back and 
covers the left port *■ again, after which live steam fills the 
port and the space connecting with it ihnnigh the small 
hole in the end of /. When the piston c strikes the stem of 
the right-hand valve i, the main valve is again shifted to 
the right and c is started on its stnjke to the left. Exhaust 
steam is confined in the ends of the cylinder to prevent the 
piston from striking the heads, in the same manner as in the 
Ktiowles steam pump. 

21, The Gorilori Steatn Pump. — If the load is suddenly 
thrown off from the ordinary direct-acting steam pump 

through any cause, as, fur c.vampk', thi; bursting of the dis- 
charge pipe or the opening of a valve, so as to permit the 
water to discharge freely under low pressure, the steam is 
liable to drive the piston to tlie end of its stroke with so 
much force as to cause serious shocks or even to break some 
part of the pump. In order to overcome this danger the 
OnrJon steam jiump is provided with the arrangement 
shown in Fig. 3, which is called an Iso<-hi'on)il valve lureur. 


12 PUMPS. § 34 

In this gear the main valve is operated by a double chest 
piston D D\ which is actuated by steam controlled by an 
auxiliary slide valve Fm the small steam chest C. F is pro- 
vided with a valve stem F\ to which two collars ^, e' are 
fastened with setscrews. A slide //, which receives its 
motion from the main piston rod by means of links /'and /", 
the lever /, and the crosshead y, strikes the collars r, e' near 
the ends of the main piston stroke, thus moving the auxili- 
ary valve F and admitting steam to the chest piston D D\ 
which in its turn operates the main steam valve and reverses 
the motion of the main piston. In order to prevent the 
pump from running away when the load is thrown off sud- 
denly, the slide H carries a cylinder in which works a pis- 
ton G fastened to the rod /? " of the chest piston D D'. This 
cylinder, called the cataract cylinder, has a cock L that 
controls a passage joining its two ends, and by means of 
this cock the passage may be more or less closed, as 

The action is as follows: Assume the cataract cylinder to 
be empty; the piston G will then meet with no resistance 
and the machine will work as usual. At the end of the 
stroke the slide // will strike one of the stops e or e\ thus 
shifting the auxiliary valve F and admitting steam to the 
piston valve D D\ which will move freely through its stroke 
and thus admit steam to the main piston for the return 
stroke. Now, if something happens to the water discharge, 
as, for example, the breaking of a pipe, the load will be 
removed from the pump and the main piston will be driven 
suddenly to the end of its stroke and thus be in danger of 
striking the head with enough force to break it. The object 
of the cataract cylinder is to overcome this danger. It is 
filled with liquid, which must be forced from one end to the 
other by the motion of the piston G. By partly closing the 
cock L a resistance is opposed to the passage of the liquid, 
and the motion of the piston G through its cylinder may be 
made as slow as desired; consequently, when the main pis- 
ton moves too rapidly, the motion of the slide H will be 
transmitted to the piston G, which will shift the main valve 




so as tu shut off the supply of stuam to the main piston and 
thus prevent the pump from running too fast. 

as. The Mar^h 6t«Hni Pump, — The Marsli valve 

motion shown in Fij;. -I iipcrates without any connection to 

the piston or rod. The steam piston a is made in two parts, 
each section being provided with a packing ring so arranged 
as to provide an annular space between the two piston halves. 
Steam at boiler pressure is admitted within the pistons by 
means of the tube b, which is rigidly secured to and is in 
communication with the chamber/-. A sluffingbox in the 
piston through which it plays prevents leakage into the main 
steam cylinder. A small port i/, shown by dotted lines, sup- 
ea steam to the chamber c. When the piston is moving 
to the right, steam is entering from the space n through the 
annular opening between the reduced neck of the valve^ and 



U PUMPS. g 34 

bore of the left chest wall /. It is thus projected against the 
insitJe surface of the valve head h before escaping through 
the port and passing into the cylinder. Both the pressure 
and the impulse due to the velocity of the entering steam 
act on the valve head // and tend to force it to the left, thus 
tending to close the annular opening in the chest wall p. 
The steam flowing through the annular opening and port / 
into the cylinder also flows through the small ports m and e to 
the left of the valve head h. The steam entering through 
these ports is wiredrawn, so that its pressure is reduced, hut 
it has a greater area of the valve head k exposed to its pres- 
sure than the steam on the right of h. Hence, the valve ^ ' 
moves to a position where the total forces acting on the two , 
sides of h are equal and then remains stationary. The 
steam entering through the annular opening in the chest 
wall / is also wiredrawn, so that the pressure on the left of 
the piston a is below the full boiler pressure existing in n. I 
While the piston a is moving to the right, the steam on i 
the right is exhausting through the port/ into the exhaust 
port/. The exhaust is first closed by the piston running ' 
over the port/; as soon as this port is covered, the port *■' 
leading to the right of the valve head li communicates with 
the space within the piston containing steam at boiler pres- 
sure, and this live steam rushes into the space to the right 
of the valve head //'. Since the steam pressure on the left 
of h is less than the pressure on the right of li\ the valve 
moves to the left, and by doing so closes the left steam 
inlet, opens the left e.xhaust, and also opens the right steam 
inlet in the chest wall /'. The live steam admitted to the 
right of the piston a first brings it to rest and then reverses 
its motion. The tappets k and k' are used for moving the 
valve by hand in case the valve is stuck. 


33. Types. — Duplex pumps, like single direct-acting I 
pumps, are made either as piston pumps or as plunger ' 
pumps. When made as plunger pumps, they may haveeitt 

§ 34 PUMPS. 15 

inside-packed, center-packed, or outside-packed plungers. 
Piston pumps are preferred for moderate pressures, but for 
pumping against very high pressures the plunger pump is 
generally used. 

84. Slide- Valve WorthfuKton Duplex Pump. — Fig. 6 
is a perspective view of a piston pattern Worthington 

duplex pump, which shows the general arrangement of the 
valve motion. The two pistons always move in opposite 
directions, and the steam valve for the cylinder ti is worked 
from the crosshead of the pistiin rod d of the cylinder c 
through the lever i/. This lever passes through the stand- 
ard (■; it is keyed to a shaft that carries a crank in line with 
it at the other side of the standard, and to this crank the 
valve rod /is attached. The valve rod in turn is hinged to 
the valve stem. The valve of the cylinder c is operated 
from the piston rod of the cylinder a through the lever ^, 
the crank //, and the valve rod /. 

25. Fig. fi is a sectional view through the center of the 
cylinder a, Fig. 5, and shows the construction of the steam 
end peculiar to the Worthington pump. Incidentally it also 

§34 PUMPS. 17 

shows one form of construction of the water end of a double- 
acting pump. The steam valve ^ is a simple D slide valve 
operated by the valve stem b. There are two ports com- 
municating with each end of the steam cylinder, of which 
the outer ones r, c are the steam ports and the inner ones ^/, d 
the exhaust ports. By this arrangement, when the piston 
approaches the end of its stroke, it covers the exhaust port 
and thus confines some steam in the cylinder that serves as 
a cushion. The valve has neither inside nor outside lap, 
and hence steam cannot be used expansively. The steam 
valve is carried along by coming in contact with check- 
nuts on the valve stem b, so placed that there is some lost 
motion between them and the valve. By this means the 
steam piston is caused to be at rest for a short time at the 
end of the stroke, which dwell allows the water valves to 
seat quietly. 

26. In the water end the water is displaced by a piston e 
provided with suitable packing and working in the cylin- 
der y. The water flows to the pump through the suction 
pipe connected to the lower nozzle and through the passage // 
to the suction valves / and k\ The water is discharged 
through the discharge valves / and ;// into the discharge pipe 
connected at n. The operation is as follows: the piston e 
moving to the left, the suction valve i lifts and the discharge 
valve ;;/ remains closed, and water flows into the right-hand 
end of the cylinder. At the same time the water at the left 
end of the cylinder flows through the discharge valve /, 
which is lifted by the flow of water, while the suction valve k 
is kept closed. When the piston moves to the right, the 
suction valve k opens and the discharge valve / closes ; at the 
same time the suction valve i closes and the discharge 
valve ;;/ opens. The pump is thus seen to discharge and 
take water during both strokes of the piston, and hence is 

27. Piston -Talve Worthingrton Duplex Pump. — 

Fig. 7 shows the steam end of a Worthington duplex pump 

§ 34 PUMPS. 19 

in which piston valves are used instead of slide valves. 
The valves are operated in practically the same manner as 
those of the pump shown in Fig. 5, but the lost motion 
instead of being between the valve and stem is obtained by 
a special construction of the valve rod a. This rod is 
divided into two parts. The part attached to the valve 
stem carries a slotted yoke b\ the part attached to the 
crank is free to slide within the yoke and carries a collar c 
pinned to it. The collar c alternately strikes against the 
check-nuts d and e on the voke b and then carries the valve 
with it. The lost motion is quite large, as the valve needs 
to be moved but a slight amount. 

28. The length of stroke is adjusted by the use of the 
so-called dash relief valves f, f. These valves control 
passages /*, / connecting the steam ports g, g and exhaust 
ports //, //, and are set by trial to the correct position and 
then locked with the cap nuts /', /'. The action is as fol- 
lows: When the piston on its exhaust stroke covers the 
port //, no further exhaust can take place, and the steam 
will be compressed between the piston and the cylinder 
head. The location of the ports //, // is so chosen that the 
compression will stop the piston just short of the cylinder 
head at the highest speed at which the pump can operate. 
It is evident that when the pump is working at slow speed, 
the compression being the same as at high speed but the 
momentum of the moving parts being less, the piston will 
stop earlier than at high speed; i. e., the stroke is short- 
ened. The dash relief valves prevent this shortening by 
providing an escape for the exhaust steam after the exhaust 
ports //, // are closed. It is thus seen that by them the 
amount of compression is regulated to suit the speed of the 
pump and the length of stroke is thus kept constant. 

Dash relief valves are applied to pistons over 14 inches, as 
a general rule, and are used with slide-valve pumps as well 
as with piston-valve pumps. In either case they simply 
control a passage by which the exhaust port and steam port 




Mt'l.Tin^-KXfAK'itUX IMneCT-Af-nXG STEAM Pl'MfS. 

SO. Itirpose.^In the simple direct-actiD}; sleani pumps, 
no use can be nude \fi the expansive force of the steam. 
They arc tbereiore, very ejcmvagant in ibe tisc of steam, 
and in order to oven^ktne thts waste to a greater or less 
extent, nuny ol the larger pumps are taade with either com- 
pound or triple-expansion cngutcs. 

30. OMiipoond Pnnip. — Fig. it shows a common method 
of arranijing the cyhnder^ tor a eotnpovnd duplex pumping 

^itgmc. The ragioe for eacfa pump is made with two cylin- 
i wtuixhI lAodem. the valves (<* boch cyhodere beti^ 
reti fro«n ibe sinvc ra]»c Metn. TTie hieh-fteasnc cyl- 
1 o«tudc and cocincfied to lite hnr-fneitrc 
t, oc Sfwrrr *-. whk^ fernts one 
r pKOoo rod passes 
* •ItowD : this sleen is bdd 
E (tipped beiweefl the sp a cer 
: otbrrwiM- the sfcere is 
[ a free 6t to tbc body. 
■ the high'prrssirc cyteder 
I ••! the kur-pCLlUTt 
a either c-yknAer. tlK 
; ptsnio is at an littcs 

§ 34 PUMPS. 21 

the resistance to the flow of steam through the ports and 
the pipe /. 

Since the volume of steam admitted during each stroke is 
equal to the volume of the high-pressure cylinder, and this 
steam, when exhausted, just fills the low-pressure cylinder, 
it is evident that the number of expansions is equal to the 
ratio of the volume of the low-pressure cylinder to that of the 
high-pressure cylinder. Also, since the length of stroke is 
the same for both cylinders, the number of expansions is 
equal to the ratio of the areas of the low- and the high- 
pressure piston. The usual number of expansions for small 
and medium sizes ranges from two to three. For large sizes 
four expansions are sometimes used. 

31. Compound pumps are also made in which the cylin- 
der arrangement is just the reverse from that shown in 
Fig. 8. In some of these compound pumps the high-pressure 
cylinder has no separate steam and exhaust ports; the com- 
pression and adjustment of length of stroke then takes place 
in the low-pressure cylinder. 

32. Triple-Expansion Pump. — In triple-expansion 
pumping engines of the direct-acting class, the arrangement 
shown in Fig. 9 is sometimes adopted for the steam end. 
This design makes all the pistons accessible and at the same 
time avoids the use of a stuffingbox between the high- 
pressure cylinder A and intermediate cylinder B. The low- 
pressure piston and intermediate piston are connected by the 
piston rod c, and the low-pressure piston is connected to the 
high-pressure piston rod by the side rods e, e and the yoke/. 
The piston rod c is nicely finished and ground and works 
through a cast-iron bushing^, which is a nice fit. This bush- 
ing can move sidewise slightly so as to accommodate any want 
of alinement between the two cylinders. At the same time 
it prevents leakage of steam from the intermediate cylinder B 
to the low-pressure cylinder C. The low-pressure and high- 
pressure stuffingboxes are quite accessible. Access to the 
different pistons is had by removing the covers //, /', and k. 

•iS. Fig. 10 is a vertical longitudinal section of the pump 
whose piston rod and cylinder 
arrangement is shown in 
Fig. 9 and shows the steam 
distribution in this form of 
pump. In the illustration. 
A is the high-pressure cyl- 
inder; Ji is the intermediate- 
pressure cylinder; C is the 
low-pressure cylinder; 1/ is 
the high-pressure distributing 
valve; and c, <* are the high- 
pressure cut-off valves. Steam 
enters through the center of 
the valve if and passes 
through the port /" and 
through the cut-off port g 
into the high-pressure cylin- 
der by way of the port //, 
° The cut-off is effected by 
fc turning the rotary valves e, c. 
Exhaust from the high-pres- 
sure cylinder takes place 
through the ports /, J and 
thence into the high-pressure 
exhaust i; which leads to the 
inside of the intermediate 
steam valve /. The valve / is 
a rotary valve designed to dis- 
tribute the steam exactly in 
the same manner as a com- 
mon D slide valve. The 
intermediate- and low-pressure 
cylinders are not provided 
with cut-off valves. The ex- 
haust steam from the inter- 
mediate cylinder passes out 
through the port in into the 

exhaust pipe «, and 
thence lo the center of 
the Idw-pressiire distrib- 
uting valve D. From the 
low-pressure cylinder the 
steam is exhausted into 
the exhaust chest / and 
thence into the condenser 
or atmosphere. Dash re- 
lief valves, not shown in 
the illustration, are pro- 
vided on the low-pressnre 
cylinders only, The dis- 
Iriliuting valves are 
worked as usual from the 
pump on the opposite 
side, while the cut-off 
valves are worked from 
o the pump on which they 

^{4, Vros» K.xhnust. 
Compound duplex direct- 
acting pumps are occa- 
sionally provided with a 
so-called cro)«s - oxhaust 
connection, the purpfjse 
of which is the keeping of 
a more uniform pressure 
in the steam chests of 
the low-pressure cylinders 
than obtains otherwise. 
As shown in Fig, U, it is 
simply a pipe a of ample 
size, which is provided 
with a valve 6 and con- 
nects the steam chests 
of the low - pressure 



cylinders. The eihaustfrom ihe high-pressure cylinders c.r 
Sows through the exhaust pipes t/.i/ into the low-pressure 
steam chests e. €. but as the steam pressure there drops 
towards the end of the stroke, there is a diminishing of the 

unpelling force on the steam pistons of the low-pressure 
cylinders that tends to shorten the stroke. With the valve b 
open, the exhaust from the high-pressure cylinder of one 
pump can pass to the low-pressure steam chest of the other 

§ 34 PUMPS. 25 

pump just when the pressure in that steam chest com- 
mences to drop, and in consequence the pressure will be 
kept more uniform, which results in a steady and uniform 


35, Purpose. — The direct-acting pump, as previously 
stated, is one of the simplest machines for pumping liquids, 
but in order to work at its best requires steam at full 
boiler pressure to be carried to nearly the end of the stroke. 
In consequence, if viewed from the standpoint of steam 
consumption, it is a very wasteful machine. The direct- 
acting pump is made more economical by making it com- 
pound or triple expansion, but even with these arrangements 
it is not possible to secure the high ratios of expansion which 
are necessary for extreme economy in the use of steam, and 
hence of fuel, and which are demanded in large pumping 
plants for commercial reasons. In the ordinary steam engine, 
and also in the flywheel pattern of pump, power is stored up 
in the flywheel at the beginning of the stroke and given out 
when expansion begins, in order to have a uniform turning 
of the engine shaft, or a nearly uniform force acting upon 
the water piston in case of a pump. In a direct-acting 
steam pump, however, there are no heavy moving parts 
similar to a flywheel, and hence ordinarily no uniform 
imp)elling force can act on the water piston if steam is 
cut off early in the stroke. This defect led to the 
design of the hlgli-dirty attachment, which is simply 
a device that stores up power during the first half of 
the stroke and gives it out again during the second half, 
thus allowing steam to be used expansively in the steam 

36. Construction. — The high-duty attachment in actual 
use was designed by Mr. J. D. Davies in 1879 and taken up 
and perfected by Henry R. Worthington. It is shown in 
Fig. 1*2 applied to a compound direct -acting pumping engine 

26 PUMPS. § 34 

fitted with Corliss valves and cutting off early in the high- 
pressure and low-pressure cylinders. The piston rods are 
arranged s^; as to avoid internal stuffingboxes, and, in con- 
sequence, the pistons are accessible without having to dis- 
mantle the pump. The two piston rods of the low-pressure 
piston and the high-pressure piston rod are attached to a 
common crosshead a, which runs in guides between the 
pump chaml>ers and high-pressure cylinders. On this cross- 
head and opposite to each other are semicircular recesses. 
On the guide plates arc cast two journal-boxes, one above 
and the other below the crosshead, equally distant from it 
and at the point equal to the half stroke of the crosshead. 
In these journal-boxes are hung two short cylinders ^, h on 
trunnions that permit the cylinders to swing backwards and 
forwards in unison with the motion of the plunger crosshead. 
Within these swinging cylinders arc plungers r, r, which 
pass through a stuffingbox on the end of the cylinders, and 
on their outer end have a rounded projection c\ which fits 
in the semicircular recesses in the crosshead. Consequently, 
as the crosshead moves back and forth, it carries with it the 
two plungers r, c, whicli, in turn, tilt the cylinders back- 
wards and forwards. These swinging cylinders are called 
cM>inponsiitln^ <\vllncU»rs; they are filled with water or 
with whatever fiuid the punij) may he handling. The pres- 
sure on the plunger within the compensating cylinders is 
produced by connecting tlie compensating cylinders through 
their hollow trunnions with an aeeuniuUitor d^ the ram of 
which moves up and down as the plungers of the compen- 
saiiiip cylinders move in and out. The accumulator used is 
A the tbtYcrential type; that is, it has a small cylinder c 
tilK'd with oil or water in which its ram moves, and above it 
has .1 much larger cylinder d filled with compressed air. On 
the top oi the ram of the accumulator is an enlarged piston 
rv>d iwrryinvi a piston, which fits closely in the air cylinder. 
TvtMn tliis construction it follows that the pressure per 
sijiMir i!u h o!i ilu' rani i>t' thr accumulator will be the pres- 
^i!Vi- . •: tiu" air in ilu' airrxlindcr per square inch multiplied 
b\ tl'i :.;'. :.^ boiwccn the aiwi ot" the air pisttMi and the ram 







r, L1N»X I 

TH.tM FP UMt /ATMilii J 

§34 PUMPS. 27 

of the accumulator. The ratio of these areas is made to suit 
the particular service for which the pump is constructed. 
The pressure in the air cylinder is controlled by the pressure 
in the main delivery pipe of the pump, as it is connected to 
the air chamber/ on the main delivery pipe. 

37. Oi>eration. — The operation of the high-duty attach- 
ment will now be explained. Suppose the pump is about to 
begin the forward stroke. At this time the water cylinders 
will be turned so as to point towards the steam cylinders, 
with their plungers at the extreme point of their outward 
stroke and at an acute angle with the line of motion of the 
crosshead, and with the full pressure of the accumulator 
load pushing them against the advance of the crosshead. 
As the pump plunger begins its forward stroke, each for- 
ward movement it makes changes the angle of the compen- 
sating plungers, until at mid-stroke the two plungers will 
stand exactly opposite each other and beat right angles with 
the pump plungers, in which position they can neither retard 
nor advance the movement of the plunger. Now, as the 
pump plunger passes the mid-stroke position, the compensa- 
ting plungers begin to push the pump plunger along, whereas 
before and up to mid-stroke they resisted the movement of 
the pump plunger. This force increases constantly, until 
at the extreme end of the forward stroke, and when the 
compensating plungers are, as at beginning, at their most 
acute angle, they exert their greatest force in helping to aid 
the pump plunger in its outward movement. The return 
stroke of the pump is made under precisely the same condi- 
tions as the forward stroke. It is readily seen that at the 
beginning of the stroke and up to mid-stroke, work is being 
done in pushing the compensating plungers inward, and that 
after the crosshead passes the mid-position, work is being 
done by the compensating plungers. The effect of this is a 
nearly uniform force on the pump piston with a varying 
pressure in the steam cylinders. 

38. An important feature connected with the use of the 
compensating cylinders is that the results obtained by their 

§ 34 PUMPS. 29 

use are independent of the speed, in which respect their 
action is better than that of a flywheel. The high- 
duty attachment in some respects also acts as a safety 
device, comparing its action here with that of a flywheel. 



39. Although direct-acting steam pumps cannot be 
excelled in simplicity, low first cost, and small expense for 
repairs, yet they can never be extremely economical in their 
use of steam, even when built compound and triple expan- 
sion. While there is little doubt that a high-duty attach- 
ment will greatly increase the economy, the fact remains 
that at present only a limited number thus fitted are in use, 
and the above statement holds good for direct-acting steam 
pumps of the ordinary design. 

40m In large pumping stations and in many other cases 
where the cost of fuel is of more importance than the advan- 
tages gained from direct-acting pumps, flywheel pumping 
engines are often used. These are steam engines with 
cranks and flywheels usually designed for the particular 
purf)Ose of driving the pump to which they are attached. 
The steam valves are driven in the ordinary way by means 
of eccentrics, or some approved automatic valve gear may 
be used to operate them. By the use of the flywheel, steam 
may be cut off at the most economical point in the stroke, 
and the surplus energy imparted to the steam piston during 
the first part of the stroke will be stored in the flywheel, to 
be given up towards the end, thus furnishing a nearly uni- 
form driving force for the pump, piston, or plunger. 


41. Fig. 13 shows a section of one side of a Hollcy- 
Gaskill compound pumping engine. The engine is double, 
the other side being like the one shown in the figure, the 

30 PUMPS. 1 34 

two engines having a comm:- flywheel and crank-shaft, 
with cranks set S«>* apart. The high-pressare cylinder is 
placed directly over the I'.'W-pressure, wiih short piassages 
between them. The conne»rt:n^-rc<is frozn the two cvlinders 
are attached to the opp--^<ite ends •:■£ a short walking beam B. 
By this arrangement the pistor.s m»>ve in oppi:>siie directions 
and the exhaust from the high -pressure cylinder passes 
directly to the low-pressure or.t:. The valves are of the 
Corliss type, with a releasing gear for regulating the cut-off 
in the high-pressure cylinder. The connecting-rod that 
actuates the crank is attached to the upper end of the 
walking Ixram. and the pxl that w«»rks the pump plun- 
ger P is atta':hed to the cr«.»sshead uf the low-pressure 

42. Fig. 14 is a front and side elevation of a modern 
high-duty tripIe-cxpansi^fU pumping engine erected at the 
North Point pumping station. Milwaukee. Wisconsin. The 
engine is of the vertira! inverted three-cylinder type, hav- 
ing the pumps in h'n^: with the cylinders, and is condensing, 
the condenser not b^-ing shown. Each piston is connected 
to a separate outside-packed single-acting plunger by means 
of pump rods, as a, a. There are four pump rods to each 
plunger, which are joined to the steam cn>ssheads^, /f and 
straddle the crank -shaft c in such a way as to allow the 
cranks (/, d to rotate freely between them. Two fly- 
wheels i\ c are emfiloyc^d to give uniform rotation to the 
machine. In the figure-, /"is the suction pipe; ^'^ is the deliv- 
ery pipe, the delivery from each chamber being connected 
to a commcMi delivery main not shown in the illustration; 
A is the air chamber ; at / are the suction valves; at k are 
ivery valves; /, / art; the plungers and ///, ;// the pump 
rs; ;/ is one of the valve chambers, the upper part of 
orms th<; delivery air chamber // and also supports 
its of the bedplates. The rear of the bedplates is 
ted on the masonry foundation. The steam cylin- 
kfC provid<rd with Corliss inlet and exhaust valves on 
Igh and intermediate cylinders and Corliss inlet valves 

ipuiiiic umiAAi. 


•%J^^^ «i*^«'r' 




§ 34 PUMPS. 31 

and poppet exhaust valves on the low-pressure cylinders. 
Large reheating receivers o^ o are used between the high and 
intermediate cylinders and between the intermediate and 
low-pressure cylinders. An air pump / is driven directly 
from the plunger crossheads and serves to remove the water 
of condensation, etc. from the condensers. An air-charging 
pump q pumps a small quantity of air into the water in order 
to replenish the air supply in the air chambers. A jacket 
drain pump r drains the water from the steam jackets. A 
suction air chamber s is fitted to the extreme end of the 
suction pipe and prevents shocks. 

43. Pumps of the design shown in Fig. 14 are used 
almost exclusively for high-duty municipal water-works ser- 
vice and are extremely economical. This type of pump 
has given a duty as high as 160,000,000 foot-pounds of work 
done per 1,000,000 British thermal units supplied to the 

44, Fig. 15 shows another type of high-duty municipal 
pumping engine. Fig. • 15 (rt') being a side elevation and 
Fig. 15 {b) the end elevation. This pump is of the crank- 
and-fly wheel type ; the motion of the pistons is not converted 
into a rotary motion in the manner shown in Fig. 14, but 
through the intervention of a rocking beam a, which is 
rocked back and forth by the high- and low-pressure piston 
and is connected to the crank and flywheel ]>y the connect- 
ing-rod b. This design, from its designer, is known as the 
Ix?avitt design. Pumps of this type have rather more parts 
than the type shown in Fig. 14, but they are not so high 
and are more accessible. The pumps are of the plunger 
type and are inside-packed; in the illustration, r, rare the 
plungers, d^ d the pump chambers, and /", f the inside 
plunger packings. The tops of the pump chambers form 
delivery air chambers. The suction valves arc located 

* The duty of a pump is a measure of its performance. It will be 
explained in detail later. 

32 PUMPS. g 34 

at // and the delivery valves are at /; the delivery pipe/ 
discharges the water through the surface condenser k^ thus 
using the delivery water for condensation. A butterfly 
valve / controls the amount of water passing through the 
condenser k. The exhaust pipe /// from the low-pressure 
cylinder enters the top of the condenser; the pipe n leads 
from the condenser to the air pump^'. This pump is double- 
acting and is driven from an arm attached to the beam a. 
Two reheating receivers /, / are used to heat the steam 
from the high-pressure cylinder during its passage to the 
low-pressure cylinder. The lower ends of the pump cham- 
bers rest directly on the bottom of the pump well, which is 
open to the river from which the pump takes its water. 
The water inlets are at q all around the base of the pump. 
It will be noticed by the arrangement of the connections of 
the steam piston and plungers to the beam that the steam 
pistons have considerably more stroke than the water 
plungers and consequently work at a considerably higher 
speed, which is a decided advantage in many respects. 
This pump, which is located at Louisville, Kentucky, gave 
the remarkable duty of 151,fJT'2,0O0 foot-pounds of work per 
l.CM^M) pounds nf dry steam used by the engine, which is the 
highest duty un record for any comp<.>und engine. 


45. Xi::ner ■;;> attempts have been made to replace the 

re^jivT- tv.:::.^ :v.'::<'ii of the pist.^ii or plunirer as used in 
ti:c .-r-.iiri.i'v :v.:r.:' by a ooniiniioiis rotarv motion. The 
rc<v.i:s ;:vt\r Veer, v.r.saiislactory i-i many oases, iuving prin- 
cipa'.'.yt" :'-:r .irhoulty in keeping:' the moving:: jxirts from 
wearing' v-.rv ratiiviiv. thus sov»n prvnliuMnvi leaka^re. 

40. Fi^^ l'"' sh"\vs on^^ k4 the voidest and at the same time 
one of the :cs: iH>tary puiiii>^. It CiMisist< ^4 a chaml^er a 
in which t\v.. :•». 'iheil wheels, or disks, /•. /' revolve in the 
direction shown l»v the arrows. The teeth of one wheel fit 



accurately into the spaces between the teeth of its mate; 

and, as the wheels revolve, 

each tooth acts as a piston 

that pushes a certain amount 

of water ahead of it, thus draw- 
ing the water from the lower 

part of the chamber to the upper 

part, as shown by the arrows. It 

is very important that the fiat 

faces of these wheels, or disks, 

should be a good fit between the 

cover and the bottom of the 

casing or cylinder, and the edges 

of the teeth also a good fit 

against the sides of the casing. 

Most of the rotary pumps that 

have been at all successful have 

been modifications of the form 

just shown, the principal differ- ''"' ^^■ 

ence being in the number and shape of the teeth on the 
rotating disks. One of these modi- 
fications is shown in Fig. 17. In 
this case the disk a has two 
^ teeth, or wings, which act as 
pistons, while its mate d has two 
recesses into which the teeth on 
.. . . ^ ' ^ ^^- '^^^ shafts of the two disks 

Jj^"Sl*' '^/)) if L ^^^ provided with outside gear- 

■'''^■- '- -^ A'?^ ing that makes their relative 

motion positive and always keeps 

them in their proper relative 


47. Fig. 18 is another modification of the rotary pump 
shown in Fig. 16 and gives a sectional view of Iloot's 
cycloldal rotary force pump. The shape of the disks or 
Impellers a, a is such that the working surfaces when in 
contact roll upon each other. Tiie sides of the casing are 

>emiLir(.ular and tin imi)t, fit closely The bearing;s in 
whith the impeller shafts A, b run are ddjiistable in all 

directions by means of wedges This is claimed to be the 
simplf^t and most satisfaiLor\ rotary pump yet produced. 

48. The tjiilnib.^ -.t-rew piimp shmvn in Fig. ]» is a 
rather peeuliar form of a rotary |.iiiii|i Tli.ri; are two 

shafts (I. (( side liy side and connected liy ihf gears /', d. 
Eath shaft carries a right-handed and a k-ft-handed screw, 

§34 PUMPS. 35 

and the right-handed screw of one shaft meshes with the 
left-handed screw of the other shaft. The water coming 
through the suction pipe attached at c flows through pas- 
sages in the casing to the outer ends of the screws and is 
drawn towards the center by the revolving scre3ys, from 
whence it is discharged through d. The screws closely fit 
the pump casing and are a close running fit on each other. 
Since the screws are right-handed and left-handed and the 
course of the water is towards the center from the end of the 
four screws, there is no end thrust. The pump may be 
driven by a belt placed on the pulley e^ or an engine or elec- 
tric motor may be connected directly to it. 


49. Centrifugal pumps depend for their action on the 
pressure produced by the centrifugal force of a quantity of 
water rotated rapidly by the vanes of the pump. Fig. 20 
shows two sectional views of a centrifugal pump and clearly 
shows its construction. The water flows through the suc- 
tion inlet a into the chamber b^ thus delivering the water to 
the inner ends of the vanes r, r, which revolve in the direc- 
tion of the arrow. When the vanes are revolved, the air 
between them is driven out by centrifugal force, thus form- 
ing a partial vacuum. Water is forced in through the suc- 
tion pipe by the pressure of the atmosphere and fills the 
space between the vanes. The water, of course, is made to 
revolve with the vanes, and the action of centrifugal force 
drives it outwards into the spiral-shaped passage ^/, which 
leads it to the discharge pipe connected to the outlet c 

60. Centrifugal pumps are most efficient when working 
under low heads and are seldom used for lifts greater than 
40 feet. For low heads and large quantities of water they 
give excellent results, and are especially useful when the 
water contains grit or other impurities that would destroy 
the pistons and packing or prevent the closing of the 
valves of other pumps. Since there are no valves or other 

§ 34 PUMPS. 37 

restricted passages, centrifugal pumps have been largely 
used in dredging machines for pumping water containing 
large quantities of mud, sand, and gravel; and, in fact, 
anything can be pumped that will be carried through the 
pump and pipes by a current of water. Centrifugal pumps 
may be belt-driven or be direct-connected to an engine or 
other motor. 


61. Deflnltlon. — Pumps in which the piston or plunger 
is driven by a crank that receives its motion through a belt 
or gearing from some outside source of power are usually 
called power pumps. 

62. Singfle Power Pumps. — A single power pump is 
one in which but one pump is driven by the shaft. This 
pump may be either single-acting or double-acting, 

63. Duplex Power Pumps. — When two pumps are 
driven by cranks on a single shaft, the combination is called 
a duplex power pump. The discharge branches from the 
two pumps are generally combined in such a way that they 
discharge through a single pipe; and by a proper arrange- 
ment of the cranks, the flow through the discharge pipe and 
the power required to drive the pumps are made nearly con- 
stant. If the pumps are single-acting and the cranks are 
set 180° apart, the discharge from the two pumps will be 
the same as the discharge from one double-acting pump with 
the same diameter of piston and length of stroke. Duplex 
double-acting pumps, with cranks set 90° apart, are much 
used and give a very steady discharge, since, when one 
crank is on its dead center and its piston, consequently, is 
at the end of its stroke and momentarily at rest, the other 
piston is moving at its maximum velocity and discharging 
at its maximum rate. 

64. Triplex Power Pumps. — Three pumps driven by 
cranks on a single shaft form a triplex pump. The most 
common application consists in the use of three single- 
acting plunger pumps with cranks set 120° apart. With 

38 PtTMPS. § 34 

such a combirtatioD, at least une of the pumps is always dis- 
charging and one taking water from the suction pipe, and 
the Dow is therefore continuous and nearly uniform. 

55, Fig. 21 shows a type of triplex belt-driven power 
pump much used for feeding Ixjilors, tilling elevated tanks in 

buildings, supplying hydraulic elevators, etc It consists of 
three single-acting plunger pumps driven by cranks set at 120° 
on a single shaft. A tight and a loose pulley provide the 
meanH for starting and slopping the pump, without disturbing 
the engine or main shaft. The pulley shaft is geared to the 
cranfe-shaft by a pinion and spur wheel. / is the suction 
inlet, /' the discharge opening, and C the air chamber. 

5H. Where the supply of power is steady, a belt-driven 
power pump is very convenient and economical for the pur- 
poses for which such inuiipscaji he used, since they get their 

§34 PUMPS. 39 

power with the same degree of economy as the engine by 
which they are driven; they are also simple in construction 
and easily operated. 

57. In locations where there is no steam or other power 
directly available, or where the use of the pump is so inter- 
mittent that a steam plant will not be economical, or where 
the cost of supplying steam is too great, power pumps driven 
by electric motors may be used to advantage. Small pumps 
driven by windmills, hot-air engines, gas engines, etc. are 
much used for supplying water to buildings that have no 
connection with public water works. Small, single-acting 
plunger pumps are most comm<)nly used with these methods 
of driving, although double-acting pumps are sometimes 
used. Where water-power is available, pumps for city 
water works or for supplying manufacturing establishments 
are often driven by watcrwhecls. 



68. Pumps intended for the drainage of mines are proba- 
bly subjected to the hardest usage of any. The water to be 
pumped is generally gritty and frequently it contatns a large 
percentage of acids; a very high pressure must generally be 
pumped against and the pump has to run almost continuously 
for long periods at the full limit of its capacity. In most 
cases the mine is located quite remote from supplies; the 
pump of necessity is underground and in a rather limited 
space; it is generally of vital importance that the pump be 
kept running in order to prevent the drowning out of the 
mine, and for the same reason it is desirable that all wear- 
ing parts be very accessible so that rej)airs can be made in 
the shortest time. Furthermore, it is desirable that the 
pump continue at work even when covered entirely with 

4.> r TIG^. i U 

pnnrs ^<zf.:i^'.— ^^zizfi z c zztt 'w rk. TT'jiile ihey do not 

i dir-i^r-rr-t irrxr^-^dTini c "r-iirr -jc^ii- Xeariy ^R mine 
ccmrs jLT-t :c "LJir? r'I"ir.;ri^r Ta.rt:;rT:. 'lz:«± ZLzmzr^z pomp, by 
rea^. c :c ih-^ :^jj?*r t-.z'z if'-zi*:zL jty%:iz^ -'an re 5t:ppei being 

oO. >£:~'t J -iinrs jjTt -t.z±TT z iz r unrs. iir^*ct -acting steam 
pu:r-rf. r t« Trr r'uiir^ 5 7 j. 7 i P'^— 7 ^ zieaat a pamp 
haviz:^ 115 Tfiz-tr --'i '.• j.i :Ji-f r^ ci ci c the mine and 
crtLrertrti t i ^r-i^irz. e^^-ri r cJ:er rt':c:r it the surface 
ij r:«is. ?:: runr:* ire ili-t lic^t tjre c =i:~e pomp and 
are still u^se-I i 5. =:-r -xtr-:. 


CORXl'-H Pl'MPlNti E^GlNlt. 

60. Vr.z:'. Trithin : n::rarj.::vt!y rtc^r.t times, the so- 
ca.Ilec Comb^h piunpiiusr eusrlne^ r^^er. the only ones 
used f' r rem vir.c the w^ter :r ~: the nvres. This engine 
was invent- : : v Watt f r u<<r :n :r.r :r..rr> t Cornwall and 
was the rir-t Tr^'.'.y erre^tivr >tv:J.:r. rr.:::r.e r.:«iv:e. An illus- 
trati- r. f a »_ rr. -h rumr.r,: r:',:.::.r s >h wn in Fig. ;i:i. 
Th-: ; ' [-7 .: > -r^lr .i:::n^ : ::^a: :>, tl^c -tr^ni acts onlv 
rr. .".-: - '.■- -"-.;:>: n. Thr : >: : r •: ." :> ^: -nnected to 
tr- - -. ^ .:: . y :-. . :'< .\ ' - v.' rn:<h pumping 

:: :::c valve in / to 
: -.wiTvis the bottom 
Tr.r W'-.^'r.z : :hv : ;:::- r vis and other 
rr. ..::.: : -.-r- : ■ :; .- ^h^::. wh::;: :.;r:> called the pit 
work. -^ ^ rr: : -i :• r.i:-e thr t:<: :: : :he tor* of the cvl- 
;ri'l»:r at.:. *- ; -.-. %:>^ , - :hv u: :xr <i,:v : the I'iston is put 
in f fjrr.:- :- ■ :r- :\ \v:\'r. the 1 --^cr -:■:«:■. The v ylinder .-i is 
steam -ja' r.-^V: : : ^v.^.^ :>. the rv'.in-icr w.r.'.s are hollow and 


' filled with steam in a manner similar to the water-jacket of 
I an air compressor, the steam entering through the pipe A', 

61. The action of the pump is as follows: Steam is 
■'admitted I'l the upper side of (he piston through a valve in /, 

« PUMPSl § 34 

which is operated by means ot a tappet rod H. The steam 
is of hig:h pressure and forces the piston rod downwards and 
at the same time raises the p:t work. This gathers momem- 
turn while \»mir.g: upwards, and the steam is cut off, expand- 
ing during the rest of the stroke. Just before the end of the 
stroke, what is termed an tj^iliT^imm ralre^ also located in 
the casing at /. opens and a!!»^ws the steam in the upper end 
»^f the cvlinvler to c^^mmunicate with that in the lower end. 
The twv> pressures being thus txilanctrd, the heavy pit work 
causes the right end of the walking beam C to descend, 
raising the piston lv> the top v^f the cylinder again. The 
exhaust valve is kxrated at L, When this is raised, the 
exhaust steam flows through the pipe M into the condenser O, 
/^ is a small pump used in ojxrating the condenser. E is a 
catch intendevi to act in case the valves should fail to work. 
The piston nxi passes between two Mocks, of which /^is 
one. the other being oppi.xs:te- If the left end of the walk- 
ing beam should descend toi.^ far, a crosspiece on the catch 
rod E is caught by the bkvks F and prevents any further 
downward movement of the piston. 


62. In Fig. *2o are shv^wn two views v^f a Cornish Bull 
engine and pump. This style of purnping engine is made by 
manv firms and c.itfers but verv !:::lc in regard to details. 
Here the walkir.o beam is disivr.sov: with and the cylinder 

is D-aced direct.v =n or :hc sh.i::. the :»:: w» rk Ivinir attached 

t" tho : i-i: :: •.:^- ".: Ir. this v\i>o .i.s ^ tho v v!:nder is single- 

i^v* "C. :" V -:v.;::: Vo::u .i::^^:::^ i Vo! w the piston instead 

■ - -^ V- ::. ..< ::: tlu' o:^:::::<' vi^ s. r::^ : in Fiij. '2't?. The 

' -' •' : -' r > ;:-.:..!;y nntUvi :n :::^ .\;^< f pumps, the 

stvrin; v\':.:;>:::^ .iivvvt'v :n:-^ the .v::n <: ::cre. In case 

tne ^vr :^.:: : : ;; ; i: w rk s::- n'vi :c c*<^--*^ »" t::an necessarv 
♦ ■•.-.* • ■.«-» * .. 

I> '. 

'^•'» * - :» ' • ;:n:: :r^ o:>.:'.".c :>.^^sc^>cs >cvoral advan- 
tai^^'T- ■ '.-. r : .V i," rn:s:; pinn.p. T'-u' iuavy walking beam 



rl V 


; «| 

44 PUMPS. § U ::> 0'"»nnec::>ns are di>per^>e<i vriih: this lessens the first 
o»^>: : the frictir. :> ;^reat:y rrcucec: :he advantage «»t having 
a viireot-actir.;^ en^ir.e is a'.s*:- ortair.ed. The principal dis- 
a-.:%\i:'.:jtce :> tha: :hr rumD b-eizj: cirectlv over the shaft, 
:ake> i:v a jcrea: ieal n :re r>:2i where space is necessary 

t>4. C :rr.:>h j.r. : Bull rur::r> r«::h use steam expansively. 
Thv V ^: ^ r. : h.**. r rv wht-rls : i:s rr the of the earlv 
.vi.. . ...e >.. xr «&..■.. u^. • e .. .... aj[a. .. .&•• w^e enu. dui 

... .._«. ...v ..^.&i ■ ..« *■'. .^ .. .&«.. « _.>*^ »i..C ^&.Ai.C^ k^.'S^. 

T-:::' r.u:r.:>r .: i\:\ir.<::r.s rar.^-^ rr.zt :. ur t tes.: that is. 
t.v: >:-:,i:r. .< . .:: :t :r :t: j t /, >tr ke. When tising more 

t "A" >\ t\VsLr-> "> ■ , jut-.f -. th-? stnir. zr-Ouce^i on the 

...!>. . ...... ..^v ......> • e . • _:r^ • * . JL.. .. -_ _ -T^.*_«-..t wear 

,1 -. ,.-k. . ...; — »,. ,. • — ■ T^ ._.&... -«^*^'^*' — .• I'.'r inc 

■ ■ ■ ■ • 

? "•; JL — ^i- ^- -u - " t . : t "-t y c ru 7 i -. T-.r^ n--': ha- ism, 

-* V" ' y^ "It I-' t'> .\LS<f J..- .ri-Uj-TT h* rli.rntal 
-*.:■•. - . sc-; .-.t t*r s.rtj.:-. v.f.-:h w.rcsth** r-unuts 

■ i" '. ' *■._ " V t' ; .■•."""•;•,■■ t "*-"-*■.».'! r«: ■" " itti. '."h'i'i. t ." the be*!!- 
* " - ' t . T t "■' ""^-i ■:.'*^tT -C th'f Ti*i ! .'ver 

• ".**• 

De .. '>. • . '^ ^ -^^ 

Ac. ■_■•-. 

!:rar.k ■. ■. i.- 

the >;t^. " 

other :;- ,, 

- - XV ■ . ; •.j.,t*. -■ WU. 

TT^^-LTS C a 


urerf :':^ - ^ . . •.; %— :^r:s 



. — -ae/rjowi.— J 






discharged into a tunnel A', about 300 feet below the surface. 
The pump rod goes straight down the shaft and the dis- 
charge pipes are placed alternately on each side of it. y is a 
suction pipe, /is a bracket, one end of which is attached to 
the pump rod and the other end to the pump plunger J'. On 
the down stroke, the water is forced out of the pump cylin- 
ders and up the pipes Q, R, S, and C^, discharging at A", L, 
-J/, and JV. The .same pit work and pump arrangement may 
be and is used for Cornish and Bull pumps. 

66, The use of a geared engine possesses several advan- 
tages over the Cornish or Bull pumping engines. The fly- 
wheel permits a more even distribution of the power. The 
length of the stroke is always the same, and there 
danger of damage caused by the piston being blown through 
the cylinder head, should the valve gear refuse to work. 


67. CoiniMirison of LlftliiK and Foree Pumps. — The 

water end of a pit pump may be a lifting pump or a force 
pump. The lifting pump is generally considered inferior to 
the force pump (which latter is almost invariably of the 
plunger pattern) for mine work. 

It is easier to specify the objections to lift pumps than to. 
state their advantages over the plunger pumps. The pump, 
rod, being necessarily inside of the delivery pipe, reduces the 
effective area of pipe and increases the friction of the water 
to some extent, owing to the added surface rubbed against. 
The rods are concealed and cannot be inspected without' 
removing the entire rod. Not only do the bolts and rods 
sometimes break, thus rendering their recovery difficult, but, 
the bolts will wear against the stocks, causing loss of power 
by friction and destroying the pipes. Lift pumps are not 
liable to sudden injurious strains as the plunger pumps. 

The plunger type of pumps is superior to the lift pump io 
nearly every respect for very high lifts with the accompany- 
ing heavy pressure or when dirty water is being raised, 



When pumping against a heavy pressure, it is impossible to 
Qjl keep the piston of lift pumps tight and pre- 

HL* vent the water from leaking. The piston 

and cylinder of the lift pump must in every 
case be a perfect fit and be truly cylindrical. 
With plunger pumps, on the contrary, the 
rod passes through a stuffingbox, and the 
plunger may or may not fit the cylinder. 
When pumping dirly water, the grit comes 
in contact with the surface that the piston 
of a lift pump is constantly traveling over 
and destroys both the cylinder and piston 
very rapidly; whereas, the plunger has to 
be kept tight at only one permanent place, 
and the dirt cannot very well get at the 
surface of the packing on which the plun- 
ger or plunger rod rubs. Every part of a 
plunger pump can be readily examined 
and repaired without being obliged to take 
down the whole apparatus. 

68. Example of a Uftln^ Pump. 

In Fig. 25 is shown a section of a lifting 
pump for use in mines. The pump consists 
of a series of pipes connected togethor, of 
which the lower end only is shown in the 
figure. That part of the pipe included 
between the letters A and B forms the 
pump cylinder in which the piston P works. 
The part above the highest point of the 
piston travel is the delivery pipe, and the 
part below the lowest point of the piston 
travel is the suction pipe. When speaking 
of these parts as applied to mine pumps, the 
delivery pipe is usually termed the worklnpf 
barrel, and the suction pipe the wind boi-e. 
In mine pumps, the lower end of the 
wind bore is pear-shaped and perforated 

§ 34 PUMPS. 49 

with many small holes to keep solid matter in the water 
from entering the pump and destroying the valves. In some 
cases, the pear-shaped end is covered with gauze for the 
same purpose. A bonnet C may be removed to allow the 
suction valve to be repaired, and a bonnet D gives access 
to the piston and its valves. The pump rod is made of 
wood strapped with iron and is connected to the piston in 
the manner shown by the illustration. 

69. Example of a Force Pump. — Fig. 26 shows one 
design of a force pump of the plunger type as used for a pit 
pump, Fig 26 {a) being a section showing the pump cylinder 
and valves, and Fig. 26 {b) showing an elevation of the 
whole water end drawn to a smaller scale. The plunger A 
is hollow, the weight of the heavy rod B and connections 
being sufficient to raise the water to the required height. 

Suppose the plunger to be on the down stroke; the valve r 
is then closed and the water filling the pump cylinder is 
forced through the valve D, which it opens, and up the 
delivery pipe E. When the plunger reaches the end of its 
stroke and begins its return, the weight of the water forces 
the valve D to its seat, retaining the water above it in the 
discharge pipe E, As the plunger moves upwards it leaves 
a partial vacuum behind it, causing the water to rush up the 
suction pipe F^ lift the valve r, and fill the pump cylinder. 
The plunger makes another downward stroke and the above 
process is repeated. A support G is attached to the delivery 
pipe, the lower end resting on a foundation. This is neces- 
sary, since the great weight of the water in the discharge 
pipe and the weight of the pipe itself would break it off at 
the bend unless supported in some such manner; otherwise, 
the thickness of the metal around the bend would neces- 
sarily be enormous. 

70. A top view of the valves is shown in Fig. 26 {c). 
They consist of six triangular valves arranged in a circle, 
with their apexes pointing towards the center. These six 
valves turn upwards on hinges and are prevented from 
going too far by the projection d \ see Fig. 26 {a). Three 




of the valves have been removed s«-> as to show the amount 
of valve oj^ening that they give. When the valves are open, 
they form an angle of about 4o" with their position when 

71* lMr|wie^^, — When putting i wna new shaft or deep- 
ening .vn V Ivi . :.e, the >>-cjLlIe\i stnkinfr pomp is used to 
drain th; \*,kter :r ni the shaft S>tt m s-.^ thai ihe work mav 
i^rvX>cxx: Thv-^^" v.::nt>s niust n^^^essanly Sr pi>rtable and 
arv >us:x ::vl;:\: : v a vh^:n att.i:h^i t eyeSxts in the pump. 
They ,;r\ a1>.^ : r '. :.::^.: w:th »r. ught-.r.'n cLjimpSv. by means 
v^: \ik"*^ . ": :-"..v :v.,k. cv jLtti.'h:fi t: the timbers in the shaft 
>fchr^' : ^ ,ii> ->'. :. h\ t*:-~ .- r« SNiti- -c temporarily. 

^:t> -::r:;.>:', ti- :*i:n rnay lue iengfth- 

end of the 

The sink- 

L~.:;>c :iSi^ vC Any mine 

:-.jL~a.:ly gTt*-y a^-d often 

' : ^Tf rcmr fr^cn aS^ve 

> . -rrutit^Iy w>:T^rs the 

" -'-en I he s. :; 

vtr \ . ^ 

v ■ ■ 

■* -C ^».*^ 


.^ -- ' 


« ^ 



$ rji . \ 

^t '^ * 

nking . 

line V 

.. » tX V, 

>■ X 

*tt ,• 

. t 

t pu:n. 

• '« "«■ ^^ 

■ •- :> i t *ie r c- 
- - r^ ' r*,r^ 

"^ '^-'^■^*i;:t^ :t 

t^tt* d f 

'' i*^ Clear" T 

g 34 PUMPS. 51 

of the pump is given in the figure. The pump has one 
plunger, but is double-acting by reason of its peculiar con- 
struction. It will be noticed that leakage past the plunger A 

is prevented by two stuffingboxes and glands placed in the 
center of the pump cylinder; a pump having this arrange- 
ment is said to be center- imfkecl. 




The action of this pump is as follows: Suppose the 
plunger to be moving downwards. The water is forced out 
of the chamber i, which communicates with the delivery 
pipe // by means of the valve C, and lifts C, thns flowing 
into //. As the pliinger moves down it leaves a vacuum 
behind it; the water in the shaft rushes up the suction 
pipe G, raises the valve /?, and fills the upper part of the 
plunger cylinder. When the stroke is reversed, the valves C 
and D close, and the valves A and B open, the water being 
forced up the pipe // through the valve E, and the cham- 
ber L is filled through the opening of the valve B. ^is the 
air chamber. The section shown by the view on the right 
is taken in a rather peculiar manner, the greater part being 
taken through the center line of the engine so as to show 
the plunger, stuffingboxes, etc., and the part showing the 
valves being taken on the center line of the valves Ji and /) 
of the view on the left. 

Electric Sinking Pump. — While most sinking 

steara-operated, elect 

1 pipe /> anil le; 

lly driven sinking pumps 
are also used. Fig. 28 
shows a duplex elec- 
tric sinking pump 
of the center-packed 
type, the stuffing- 
boxes being shown 
at //. The two 
plunger rods £ and F 
operate the plungers. 
^^^P" A clamping piece D 
is used for attaching 
the pump to the 
shaft timbers ; an eye- 
bolt G is used for sus- 
pending the pump 
from a chain. The 
water enters through 
!S through the discharge pipe A, 




An air chamber C is fitted to the valve chamber. The elec- 
tric motor is within the water-tight casing above the water 
end and is protected by it, so that the pump can work just 
as well under water as above it. 



74. Pumps Used. — Direct-acting steam pumps used for 
mine drainage are almost invariably of the plunger pattern. 
Most of them are duplex, but a number of single double- 
acting steam pumps are in use. Formerly, all the mine 
steam pumps were simple direct-acting pumps, but of late 
years compound and even triple-expansion pumps have 
grown in favor, and even crank-and-flywheel pumps driven 
by compound Corliss engines are now extensively used on 
account of their superior economy. Most of the pumps are 
of the double-plunger type, there being two plungers to each 
water cylinder, and the stuffingboxes are located on the out- 
side, thus making the pumps outside-packed. Some mine 
pumps are center-packed and use but one plunger for each 
water cylinder. 

75. Simple Double-Plungrer Pump. — Fig. 29 shows a 
side view of a simple direct-acting single mine pump of 

Fig. 29. 

the double-plunger type. The two plungers F and F carry 
yokes H, H at their outer ends and are tied together by 



i 34 

side rods, as /. The plunger /-' is attached directly to the 
piston rod P. Suppose the steam piston in ZJ to be moving 
to the right; the plunger F is then forcing water into the 
chamber 6* and up the discharge pipe -4. Since the plunger/^ 
is moving out of the water cylinder (it will be understood 
that the cylinders in which /'and /■' work are divided by a 
water-tight partition at .V), water flows in through the suc- 
tion pipe, and when the pump makes its return stroke, F' 
dues the forcing while water flows into the cylinder in 
which F works. It is thus seen that by the use of two 
plungers connected as shown, the pump is made double- 
acting. Stuffingboxes A' and K' are used for packing the 

76, Coinpoiin<l Doiible-PIiinKer Pump. — The internal 
arrangement of a double-plunger pump is shown clearly in 
Fig. 30, which is a sectional view of one side of a Jeanesville 
compound duplex mine pump designed for heavy pressures. 
The section shows one of the plungers E working inside its 
chamber; G is the partition that separates the two cham- 
bers. The outer end of each plunger is supported by a 
shoe A' working on a slide /. L is the suction pipe with 
branches leading to the suction valve chambers F, F\ the 
discharge valve chambers //, H connect with the discharge 
pipe shown just over the pump cylinders. As shown in the 
figure, there are two suction and two discharge valves for 
each plunger. The usual arrangement for pumps of this 
size is to have a great number of small valves instead of a 
few large valves, as shown, but for mine work the sulphur in 
the water destroys the valves rapidly and the large valves 
are more quickly and cheaply replaced. A is the main and 
B the auxiliary throttle; C is the high-pressure cylinder, 
from which steam goes to the low-pressure cylinder through 
the pipe D. The valve gear of the steam end is prac- 
tically the same as that of Worthington pumps, and the 
steam valves of one side are operated from the piston rod 
of the other side. Steam is carried full stroke in all 

2!L.':?:^'.>'-t / 






77. Triple Exi>ansion Center-Paekeil Pump. — Fig. 31 
is a side view of one side of a triple-expansion duplex Worth- 
ington mine pump having plungers which are center-packed. 

FlO. 31. 

The type of water end Used with this pump has been given 
the name of Scrti^nton tyi>e by the makers. Sectional 
views of the steam cylinders of this pump have already been 
given in Figs. 9 and 10. The plunger a is connected to the 
piston rod b and works in the pump chambers r and d^ which 
have the suction valves on the bottom and the delivery 
valves on top. The suction pipe is connected at e and the 
delivery valve at f. An air chamber f^ on the delivery 
absorbs shocks and promotes a steady delivery. The pump 
is double-acting. 


78. Fig. 32 (a) is a side view of the high-pressure side of 
a duplex pump driven by a cross-compound Corliss engine, the 
pump being of the double-plunger type. Fig. 3"^ (^) is an end 
view of the water end of both pumps, looking towards the 
engine, and Fig. 32 {c) is an end view of the engine, looking 
towards the flywheel, the observer being supposed to stand 
between the pumps and the engine. The plungers a and h 
are connected by yokes r, c and rods d^ d and are driven 

'V5 PUMPS. 8 -^ 

(lirertly by the piston rods of the high-pressare and low- 
pressure cylinders, which for this purpose are prolonged 
Iwryond the pistons and pass through the back cylinder 

70. The pump cylinders have the necessary diaphragm € 
in the <:cntcr, and each pump cylinder has two valve cham- 
bers /, /' c<mtaining the suction valves and two valve 
' hamlxfrs;^'',;^^' containing the delivery valves. These valve 
' h.'ifiibers are placed on both sides of the pump cylinders. 
The four suction-valve chambers of each pump connect to 
the < onunon suction t)ranch A, and the two branches in turn 
are * r^nneeted to the suction main by a Y fitting not shown 
in the illustration. The four deliverv chambers of each 
pijinji are connected together by branch pipes, and these 
bianrh pipes in turn discharge into a common main delivery 

H4K A reheating receiver / is placed between the high- 
pie-.'-ure and low-j^ressure cylinders. The low-pressure 
^t.«ain ifilet valves are placed l>eneath the low-pressure cylin- 
der; ilie low-pressure exhaust valves are on top and exhaust 
dire< ily into the condenser k, which is placed on top of 
the low-pressure rylinder. The high-pressure valves are 
arranged in the usual way. The engine is provided with a 
variable sf>eed Porter governor /, by means of which the 
s[>eed of the engine may be varied to suit the requirements 
of the service. 

81. The particular pump illustrated has cylinders 

ndies and 00 in<;hes in diameter and a 48-inch stroke, the 

Igiers being y.\\ inches diameter. It was designed by 

Dickson Manufacturing Company, of Scranton, Pennsyl- 

*, to pump water highly charged with sulphuric acid 

ist a head of TOO feet. To guard against corrosion, the 

\ cylinders, valve chambers, and all pipes were lined 

1 lead and the plungers and valves made of acid-resisting 

Qposition. Owin;^ t<» the hiirh ec'»n«>mv possible through 

re u*^ of a c«»mp«>invl cr.ndcnsini: C<«rliss engine, this is 

Jtly called a ** high-duty mine j.ump " by the builders. 


.' »l 

§ 34 PUMPS. ■ 57 



82. A displacement pump is a pump in which there is 
a complete absence of moving parts and where the fluid to 
be pumped is moved by steam or compressed air. Of 
the steam-operated displacement pumps, the best known is 
the pulsometcr; the Harris compressed-air direct-air-pressure 
pump and the PohU air lift are the best known air-operated 
displacement pumps. 


83. Fig. 33 shows a perspective view and Fig. 34 a 
sectional view of a pulsometer of the latest manufacture. 
In the sectional view the full lines represent the left-hand 
half and the dotted lines indicate the position of the dis- 
charge valves in the right-hand half of the pulsometer 
shown in Fig. 33. In the following description, the letters 
refer to both figures: The steam pipe is connected at E 
and the suction pipe at S. C is an air chamber that has no 
connection with ^ and A^ but communicates with the suc- 
tion pipe by means of the opening / situated below the 
suction valves /"and C The two latter valves are made of 
flat rubber and are held to their seats, as shown in the 
figure, by means of the spindles R and T, The spindles are 
raised and lowered, as the case may require, by means of 
the bolts y and e. //, //^are plates that may be removed to 
facilitate the examination of the valves. Z) is a hard-rubber 
ball that acts as a valve for admitting the steam to the cham- 
bers A and B. J/ and iVare exhaust valves, also made of 
rubber and situated in the chamber A attached to the 
other half of the cylinder. They are raised and lowered in 
the same manner as the suction valves by turning the 
bolts g and h. K is the delivery or column pipe. 



84. The action of the pulsometer is as follows; Boih 
chambers /( and B are filled with water to about the height 
of the water in B, Fig. 34. The valve (/is then opened and 
the steam enters one of the two chambers A and B. Sup- 


pose it enters B, the valve D being at the right, as shown. 
The water in B will be forced through the delivery valve N 
into and up the column pipe A'. This will continue until 
the water level gets below the. edge of the discharge 

8 34 


opening^ P. At this point the steam and water mix in the 
discharge passage and the steam is condensed, creating a 
vacuum in B. The pressure in A is now greater than that 
in B, owing to the vacuum in B, and the ball valve D is 
shifted to the left, the steam entering the chamber A and 

driving the water through M into the passage O and column 
pipe A" in the manner just described. While this is being 
done, the pressure of the atmosphere forces the water up 
the suction pipe S, opening the suction valve F, and into 

U.S. V.-5 

60 PrMPS. § 34 " 

the chamber P. filling it. When the suction valve is closed, 
owing lo the rcshifiing of the ball \'alvc D to the other side. 
the suction water enters the air chamber C through the 
inlet / an<1 is biMught gradually tu rest by the compression 
of the air in C, thus preventing a shock owing to the sud- 
den sioppjige of the inflowing water. When the water in A 
has reached the level shown, the steam in A is condensed, 
the hall /) is shiftetl to the right, and B becomes the driving 

HA. In Fig. 33 are shown three small air ralves a, b. 
and f. The \-*lve ( admits air to the air chamber C. to 
replenish that which is K»st through leakage and through 
ulvw^rplion by the water. The valves a and * admit a small 
tjnaitiity of air to the chambers .-I and B. respectively, just 
t>efore the suction begins. This injures the suction some- 
what, but is nei-«^ssary fof two reasivs: First, it acts as a 
rrituUtor, |>o\'ernin}; the amount of water admitted to the 
chainlwni: and. so-ood. it presents the steam from con- 
densing before the water gets below the edge of the dis- 
otvari^r outlet. These vaI^'vs open inwards, as before stated. 
Supp^iNr there is a vacuum in A owing to the ooadensation 
vt the steam The atino6ftbcric prrssare forces open the 
\«1\«4 And Mihttit» a bttV air to ibe cylinder. The incom- 
• tikis jur and soon closes the \'alve. 
--.-■atpncssni to such an extent as to 
<■ ■■ --^iiw trf tfce atmiwpbcre. the suction 

More water can get in. Since the 
ki.y . . .», .y, iiM other chambcf-, ii is evident that 
uni J air wtwwttwl cootix^fe^ the anooat of water 
t •Ui--<vi; A* «atci)>.ta mrk*!. »e«e water entering 
fn ^ le*« »rf ■-: rV- ^imber aod vie* versa. The 
.■xi by txrmiBg ibe ralvej s 
<cd t^t the sactioQ valve 
«i i>)e nsLaat tbe b«S is shifted 
|»^ the stv«m. 
j^fRVtMsthcstaom inMi commc in con- 
r ♦■ rtt the KtrtSais yvonsE. imtil the 

§ 34 PUMPS. 61 

water level has sunk below the edge of the discharge orifice. 
Air being a poor conductor of heat, the steam does not 
condense until the mixture of the steam and water has 
taken place. 

86, When the barometer stands at 30 inches, the pulsom- 
eter will raise water by suction to a height of about 
26 feet, although it is not advisable to exceed 20 feet, and 
force it, when necessary, to a height of 100 feet. It has no 
wearing parts whatever except the valves, which are easily 
and cheaply repaired. It will work in almost any position, 
and when once started requires no further attention. 
There are no parts that can get out of order. It will pump 
anything, including mud, gravel, etc., that can get past the 
valves. Its first cost is low and it requires no foundations 
to set up. There is no exhaust steam to make trouble and 
no noise. 


87. The direct-air-pressure pump here shown is the 
design of Professor Elmo G. Harris and is one of the simplest 
forms of pump. The pump is shown in diagrammatic form 
in Fig. 35. There are two pump tanks a and b, which are 
fitted with suction valves c and d and discharge valves 
€ and/". The two tanks are connected to the common suc- 
tion pipe g and both discharge into the same discharge 
pipe //. The tops of the pump tanks are connected by 
pipes / and k to an air compressor ;//, and by means of an 
automatically operated four-way cock /, either tank can be 
connected to the compressor side of the air compressor. 
The operation is as follows: with the cock /in the position 
shown, the tank b is connected to the suction side of the air 
compressor, and hence a vacuum is formed in the tank b. 
Consequently, the water in the supply is forced by atmos- 
pheric pressure up the suction pipe g^ lifts the valve d, and 
passes into the tank b. At the same time the tank a is con- 
nected to the compressor side, and the air pressure on top of 
the water forces it out, the water holding the suction valve c 


closed but opening the delivery Talve t- and [lassing up the 
discharge pipe A. When the tank •* is nearly empty, ihetank^ 



f!_OtB coct / is then turned autnmaticatly so as 1 
k a in communieation with the sucticm side 1 

S5 34 



of the air compressor and the tank b in communication with 
the compressor side. The water now flows into a and out 
of b, and the cycle of operations is repeated as long; as the 
air compressor is working. The height to which water can 
be forced obviously depends on the pressure to which the air 
is compressed. 

THE POHL^'aIK lift. 

88. The Pohle air lift is much used for pumping water 
from artesian wells; it is operated by means of compressed 
air and has no moving parts. It is not affected by sand or 


grit and the water is benefited to a considerable extent by 
the action of the air, in that it purifies and cools the water 
while it is being pumped. Other advantages claimed for 




this device is that it increases the yield of an artesian 
well from two to five times; also, the full area of the well is 
available for a flow of water. Compressed air is supplied by 
means of an air compressor at the surface, which may be 
located in any convenient position, or one air compressor 
may supply several artesian wells. 

89, The operation of the pump is as follows: Two 
properly proportioned pipes are inserted in the well, using 
either of the three arrangements shown in Fig. 3B. Com- 
pressed air is supplied through the pipe a to the bottom of the 
well tube d. At the beginning of the operation the water 
inside and outside of the pipe is at the same level. 
When air is forced in through the pipe a, it forms alternate 
layers with the water, so that the pressure per square inch 
of the column thus made up of air and water inside of the 
water pipe is less than the pressure per square inch outside 
the pipe. This difference of pressure causes a continuous 
flow from the outside to the inside of the water pipe, and its 
ascent is constant and is free from shock or noise of any kind. 
The strata of compressed air in their ascent prevent any 
slipping back of water. As each stratum progresses 
upwards to the spout, it expands on its way in proportion 
to the overlyiQg weight of water, so that the pressure of the 
air gradually becomes less and finally reaches the atmos- 
pheric pressure. 




90, Reciprocating pumps are either single-acting or 
double-acting. Single-acting pumps are either lift pumps, 
one of which is shown in Fig. 3S, or out side- packed plunger 
pumps with one plunger, as_ shown in Fig '^6, or outside- 
packed double-plunger pumps, as shown in Figs. 39, 30, 
and 33. Double-acting pumps are force pumps of the piston 



or plunger pattern. Piston pumps, by reason of their crin- 

struction, are inside-packed, and such a pump is shown in 

Fig. 6. Double-acting plunger pumps are inside-packed or 

center- pa eked. Attention is here called to the fact that 

I outside -packed double- plunger pumps are often, but errone- 

1 ously, considered as double-acting. While they give a dis- 

[ charge equal to that of a double-acting plunger pump, it is 

[ obtained by combining two single-acting plunger pumps to 

L discharge into the same delivery pipe, and hence it is incor- 

L rect to call such a pump a double-acting pump. They are 

I properly called duplex puinp»«. 

V 91. Fig. 37 shows the water end of a (]ou1>lc-actlng 
Inside- pocked plnn^cr pump. The pump chamber is 
divided into two parts by a partition a, through which the 

[iliingcr b wiirks hack and forth. A water-tiyht joint betwi 
the pUiimcr and partition is made either by a closely fittm| 

tfeRTSMlvvtUhr ( 

§ 34 PUMPS. 67 

of suction valves //, //' and delivery valves ^, e\ The water 
enters the pump through the suction pipe, which is connected 
at / and flows into the suction-valve chamber g^ from whence 
it passes to either side of the partition a and then into the 
delivery-valve chamber //and into the delivery pipe connected 
at /. When the plunger moves to the right, it displaces the 
water on the right of the partition a\ the suction valve d' is 
closed by the pressure existing there, while the delivery 
valve e' is open and the water discharges into //. At the 
same time the plunger creates a partial vacuum at the left 
of the partition a and, hence, water flows through the open 
suction valve d into the left pump chamber. The delivery 
valve e is kept closed by the pressure in //. When the plunger 
moves to the left, the suction valve d' and delivery valve e 
open and the suction valve d and delivery valve e' close. It 
is thus seen that the pump discharges during either stroke 
of the plunger, i. e., the pump is double-acting. 

92. Fig. 38 shows a sectional view of the water end of a 
center-packed double-acting plunger pump, the stuffing- 
boxes a and b being used for packing the plunger c. The 
action of the pump is identical with that of the pump shown 
in Fig. 37, that is, when the plunger moves to the right the 
suction valves d^ d and delivery valves r, c are open and the 
suction valves y,y and delivery valves^, ^are closed. When 
the plunger moves to the left, the suction valves/, /and 
delivery valves g^ gare open and the suction valves d, d^nd 
delivery valves^, e are closed. 

93, The water end of a double-plunger pump for high 
pressures is shown in Fig. 39. The two plungers a, b, as 
usual, are connected by yokes and side rods outside of the 
pump. The rods /, / tie the water end to the steam end. 
Each plunger has its own suction valve c and delivery valve/. 
The suction valves communicate with a common suction 
chamber, to which the suction pipe c is attached. At d the 
discharge pipe is shown. Plugs g, g when removed give 
access to the valves. A standard // supports the water end 

C8 Pl'MPS. §34 

on its foundation. The illustration clearly shows that each 
plunger is single-acting, but that the discharge is equal to 
that of a double-acting pump. Pressure pumps do not differ 

in their operation from ordinary pumps; all parts are simply 
made extra heavy so as to stand the high pressure, and for 
very high pressures steel is substituted for cast iron in the 
water end. 

94. Fig. 40 shows in diagrammatic form two forms of 
a plunger pump that is double-acting and is known as a 
(IlS'ei-eiitial pump. Its distinguishing feature is that it 
needs only one set of suction valves and delivery valves. 
Fig. 40 ((?) shows the arrangement used for two plungers a 
and b, which are connected together by yokes and side rods. 
In Fig. 40 {fi), the two plungers are connected directly 
together. In both designs one plunger, as a, has exactly 
double the area of the other plunger b. This fact must be 
carefully borne in mind. Since the stroke of both plungers 
is the same, it follows that the larger plunger in Fig. 40 (a) 
will displace double the quantity of water that the smaller 
plunger displaces. In Fig. 40 (i). the left-hand side of the 
plunger a displaces double the quantity of water displaced 
by the plunger b. In both designs c is the suction valve 
and (/ the delivery valve. 

95, The operation of the differential pump shown in 
Fig. 40 {a) is as follows: The pump being filled with water 
and the plungers moving to the right, the suction valve is 

§ 34 PUMPS. CD 

open and the delivery valve closed, The plunger b, or the 
ri^hl-hand side of the plunger « in Fig. 40 {b), forces a 
volume i)f water equal to its displacement out of the cham- 
ber f and up the delivery pipe /. At the same time, double 
the volume of water is drawn into the suction chamber //. 

Now. assume that the plungers move to the left. The suc- 
tion valve is then closed and the delivery valve is open, and 
double the quantity of water discharged during the stroke 
tn the right now flows into the chamber e. But while this 
is going on, the volume of the chamber e increases by the 
ceding of the plunger b. or the outward movement of the 
ilunger a in Fig. 40 {h). by an amount that at the end of 
'the stroke is equal to exactly one-half the amount dis- 
teharged into it, so that the outflow into the delivery pipe is 

70 PUMPS. g 34 

only one-half of that discharged into the chamber c. This 
outflow is equal to the displacement of the small plunger. 
or the right-hand end of the plunger a in Fig. 40 {b), and 
hence the same amount of water is discharged during both 


90. Development. — RleUler puin|>s are the invention 

of Professor Riedler and are a type of pump designed for 
running at very high' speeds. By study, experimenting, and 
carefnl noting of cause and effect, he discovered several very 
important phenomena. He found that there was much 
greater resistance to the flow of water through the valve 
passages and ordinary pumps than was before this thought 
to exist. He further found that the slip of ordinary valves is 
very large, and that even when small has a great tendency to 
cause severe hydraulic shocks throughout the pressure parts 
of the pump. He also was aware that the frictional resist- 
ance to the passage of a certain quantity of water through 
a large number of small openings is much greater than that 
existing when the same quantity of water passes through 
a single opening equal to the combined area of the 
smaller ones. With these facts in view. Professor Riedler 
designed a pump valve having the useful valve area as 
large as possible and containing as few separate passages 
as is consistent with good construction. He substituted 
one large valve for many small ones, thus decreasing the 
friction of the water in the valve passages. The reduc- 
tion of the slip was accomplished by arranging a mechan- 
ical controlling device, whereby at the proper time and 
without restricting the water passage the valve was closed. 
The mechanical controlling device further assists in the 
reduction of friction in the valve passages, as it permits 
the valve lift to be high, thus increasing the effective area. 

97. The first pumps fitted with Riedler valves were con- 
structed in 1884, since which time more than 1,500 pumps 
have been built. These pumps are adapted to any service 

§ 34 PUMPS. :i 

to which pumping machinery may be applied. They are 
built in all sizes, ranging in capacity from 115,000 gallons 
in 24 hours to 20,000,000 gallons in 24 hours, and are work- 
ing under heads as high as 2,480 feet and at speeds as high 
as 120 revolutions per minute, and with piston speeds as 
high as 60(5 feet per minute, which, by the way, is the 
av^erage speed of steam pistons. 

98. Valve Gear. — Fig. 41 shows an outside view of 
a direct-connected electrically driven differential Riedler 
pump having the plunger arrangement shown in Fig. 40 (d). 
The pump valves are closed by cranks, the crank a opera- 
ting the suction valve and the crank d the delivery valve. 
The two cranks are operated from a wristplate c similar to 
that of a Corliss engine and to which they are connected 
by the rods shown. The wristplate is rocked back and forth 
by the eccentric ti on the crank-shaft, to which it is con- 
nected by the eccentric rod e. The plungers are driven by 
a crank, as shown. 

99. Riedler Valve. — Fig. 42 shows a detail of the 
improved Riedler suction and delivery valve. Both suction 
and delivery valves are alike in these pumps except as 
regards the flange for securing them to the pump cham- 
bers. The valve proper consists of three concentric bronze 
rings a, 6, and r, each of which is cast in one piece and which 
are set into a spider ii having eight arms. This spider is 
free to move up and down on the central valve post, or valve 
spindle e. This valve rests on a heavy cast-steel valve seat/ 
having three annular openings a', b\ and c\ The valves 
proper are not rigidly connected to the spider, but each 
valve is free to form its seat with the valve seat and inde- 
pendent of the spider or each other. A leather ring between 
the valve proper and the spider serves to make an absolutely 
tight joint. A circular nut g is secured to the top of the 
hub of the valve spider ^/and holds in place a steel pressure 
plate h. This pressure plate rests on top of a spring cap /, 
below which a spring k of soft rubber is placed. This rub- 
ber allows of a certain amount of yield between the valves 


xad its seat in case any foragn aaxtcr shovM get betvccn 
than. IVo stcd fingo^ boC Au wu in the dravtng, press 
t^ma tiM pressnie plate and serve to dose the valrc jost 
before iIk piston reacts tbe end ci its iXmke. A water 
B /, the object of vbich is to prereot the Talve from 
1 to tbe lop of the 
e r by the ant ■. The not £■ is dusely fitted to tbe 
mber in /and traps the water in front trf it. thus making a 
hydraulic coshioo. The valve seals are se<?nred in the x'alre 
chambers by wed^-sbaped plags a. «. n^icb are forced in 
by stods and nats tluiM^ the gland #. the effect being to 
force tbe valve seat / hard down oo its bearing / in tbe 
pomp chamber. 

100. Fig- 43 b a perspective view td the Rtedler valve 
and seat, showing tbe operating mechanisaB br roeaos of 
wbich tbe valve is seated. All visible parts are lettered the 

Fig. 4^, The crank ^ is operated froin the 

bown in Fig. 41 : it ts keyed to a shaft r, which 

nuffingbi>i s bolted to the valve chamber 

> a forked crank at its inner end. The jaws or 

f of the fiirked crank press upon the pressure 

t tbe valve at the proper lime. The motion of 

timed in relation to the motion of the 

g 34 PI? MPS, 

plungers that the fingtrs are cles 
when the plungers begin to dtlivi 
valve free to open. 

ssiire plate // 
s leaving the 

101. The Riedlcr valve is by no means confined only to 
water pumps, ll lias been and is nsed siirressfiilly for high- 
pressure air and gas compressurs. The Kicdltr pump may 

be driven by a steam engine, electric motor, tarbine, w; 
wheel, by belting, or in any other conrenieot manner. 

103. Riedlcr Express Pnmp.^A type of Riedlcr pump 

that has recently been bronght oat for running at a very 
high speed is called the Rledler express pump and is 
shown in Fig. 44. Although the ordinary Riedlcr purap can 
be run at speeds as high as 15(1 revolutions per minute and 
sometimes faster, conditions arise requiring a much higher 
speed, and t>> meet this condition this special design, which 
may be run at speeds as high as 300 revolations per minute, 
has been developed by Professor Riedler. Tbe main feature 
of this pump — in fact, the part that permits running at such 
high speeds, is its suction valre. As will be seen by referring 
to the figure, the suction vaJvca is annular in form and is 
concentric with the plunger ; it lifts in the direction opposite 
to that of the plunger when on its suction stroke, tbe watet. 
Bowing from the suction chamber ^i into the valve chai 
ber f. At tbe end of the suction stroke a buffer J mounted 
upon the end of the plunger drives the suction valve to its 
seat, making it certain that the valve is seated when the 
plunger starts on its delivery stroke and allowing praciically 
no slip. .\ high suction air chamber *■. containing a column 
of water, is placed above the suction valve, making it cer- 
taaa that tbe pump will SII as the plnngerymakes its 
I stroke. The delix-erv val^-e is shown at.f- It will 
1 thJit tbis pump is of ibe differential type. 


. 103. The chief point of advantage of the cxpms pump 
« that it may be conDected to high-speed motors. It ts ff 
mensions compared to the quantity i^f water it < 
ar:'' . and thus >.iinsequent)y low in first cost. Ab« 
'"■'-■ ■ these pumps hai-e been c»>nstructed up to 1 
if !.-'l. ranging in capacity from l.' galloos 
hours to T.p.i"i_rt«)n gallons in -ii hours, and in speed i 
b as 3<ii' rrv 'jtioos per minute, pumping against a head 
10 feet:'ors ha%'e been built to pump against a bead 
t feet at 2tKi revoluttoos per mtnatc. 




LO thifl 
MIS idi^ 



(PART 2.) 




!• The smaller sizes of pump plungers are usually made 
of solid round bars of metal turned smooth, so as to work 
through a stuffingbox with as little friction and wear as 
possible. For larger sizes the plungers are frequently of 
cast iron and are often made hollow to reduce the weight and 
amount of material required. Incidentally, it may be 
remarked that a hollow plunger is easier to move than a 
solid one, all other conditions being equal. This is due to 
the fact that the water buoys up a hollow phinger more than 
a solid one. In large horizontal pumps hollow plungers are 
often so proportioned that they actually float in the water, 
thus relieving the stuffingboxes of the weight of the 
plungers and reducing the wear. 

2, Fig. 1 shows a simple form of solid plunger pump, 
such as is often used for feeding boilers. The plunger works 
through a stuffingbox of the ordinary pattern, packed with 
hemp or some of the common types of soft piston-rod 


For notice of copyriy^ht, see paj^e immediately ft)Il<>\vin)if the title page. 

& FIC-ls 

i ikraE stTles at bf^E, IhAot. cast-inei 



, TP 

ictlwd» <•{ attacfaiB^ tbcm to tbc pampl 
ruds. The packing for these 
plumersk wbcn used for 
BMinate prcsssres; 
BsaaUr bcmp cootJuaed in a 
stnffiogbox (rf tbe ordinaryi 

4. When the prcssait! 

under vhicfa tbe 
wurks is very heavy^ 
U-siuped katbrr packing 
is sonKtimcs usrd. P'g. < 
shows three methods oC 
huldiog thc% rap Irath.- 
ers, as they are calkd. Thi 
section at {6) shows thfl 
leather .■ held in a i 
cusi in the u{>pcr end ct t 




pump cylinder. In this case it is necessary tu remove the 
plunger D in order to insert a new leather nr to examine an 
old one. Experience also shows that the leather bears 
against the plunger with the greatest force at the bend />' 
and fails at that point first. In {c) the leather is held in its 
recess by a gland s, and is also supported by a brass ring C, 

which prevents the severe pressure of the leather against 
the plunger at B. A more elaborate packing is shown at (a) \ 
the gland s is lined with a brass ring w/, which holds the 
leather o down on a brass supporting ring /, A chamber « 
in the gland serves to hold oil for lubricating the plunger. 

The form of packing shown at (/') is cheap, but in addition 
to the difficulty of inserting the leather, it is difficult to 
cast the recess so that it will fit the leather pniperly. In 
either of the forms shown in («) and (r), the gland can be 
accurately turned to bear against the curved portion of 
the leather, thus forming a better support and increasing 
the life of the packing. 

5. Fig. 4 shows an inside-packed plunger with a remov- 
able stuffingbox designed for hemp packing. This con- 
struction is better than merely providing a close-fitting 
bushing, especially when the water is gritty and thus liable 
to wear the plunger. 

4 PUMPS. g 35 

In^itle-packed plunger piimps have several disatlvantages. 
When the packing bccumes worn, the heads of iho pump cyl- 
inder must be removed in order to tighten or renew it, and, 

besides, there is no way of detecting lealcage when the pump 
is working. \\ nh gritty water espetiall> when working 
under high pressures, these disadvantages become serious. 
6. Fig. 5 shows a good arrangement of plunger, stuffing- 
box, and gland. This type of plunger and stuffingbox is 


much used in mining pumps. The plunger cap a is made of 
acid-resisLiiig metal, while the plunger h proper is made of 
cast iron, it having been found in mining work that the 



plunger cap or point is the only part that is attacked by 
acid water. Apparently the play of the plunger through 
the stuffingbox and grease prevents the water attacking its 
surface. An improved form of sfrea**!* rliiji: is shown at c. 
This ring fits into the stuffingbox and is placed between the 
rings of fibrous packing. It is recessed both inside and out- 
side and has several holes by which the outside recesses 
connect with the inside recesses. The outside recess is in 
connection with the grease cup </, which is provided with a 
cock. When it is desired to grease the plunger, the cock is 
opened and the grease forced in the space around the 
grease ring by the screw e on top of the grease cup. 
This is done once or twice during the day, and the cock 
is then closed so as to relieve the grease cup of the water 
pressure and to prevent consequent leakage. The stuffing- 
box is bolted directly to the pump chamber, which may 
be of any type, but for high-pressure mine work it is gen- 
erally circular. This type of plunger and stuffingbox has 
been used with much success in the anthracite coal regions. 


7, Pistons for force pumps are made in a variety of forms. 
Fig. 6 shows a piston with fibrous packing held in place by 
a follower. The follower 
is fastened to the piston 
by means of an extension 
of the piston rod beyond 
the nut that holds the 
piston in place. 

8, An excellent pack- 
ing for small pistons is 
shown in Fig. 7. It con- 
sists of a metallic piston made up in three parts, between 
which are clamped two cup leathers, as shown. 

9, Pistons for suction and lift pumps must be provided 
with valves that allow free passage for the water through 

Fig. 6. 

6 PUMPS. g 35 

the piston in one direclimi and prevent its return. These 



and has no separate packing. 

y design that will furnish the required 
area of passage and at the same time 
will be strong enough to withstand the 
pressure of the water. 

10, For small pumps and moderate 
fts, leather clack valves, Fig. 8, are 

often used. They consist simply of a 
leather disk held at one side and 
strengthened by a metal plate on top. 
The leather when wet forms an excel- 
lent hinge and a tight valve. Leather 
clack valves are also used for the suc- 
tion and delivery. 

11. For lift pumps working under 
hii-h pressures, the valves shown in 
Fig 9 give good results. The piston 
shown at (it) has a rubber disk valve 
working on a gridiron seat. The valve 
IS guided by a central spindle s and is 
held on its seat by a light helical Spring 
that acts on a plate on top of the 
rubber disk. This piston is very long 


I'i. The valve shown at {/') is for very heavy pressures. 
h consists of a metal disk guided hy a central spindle s and 
held down by a helica! spring in the same manner as the 

bbtier valve. The piston is made with a follower plate for 
ue purpose of holding a hbrous packing in the same r 
s Ihc piston shown in Fig. (i. 


The most important details of a pump of any kind 
e the valves. They must be so designed and constrm-ted 
tat they will fulfil ail the following conditions as thoroughly 
p possible : 




(«) Tbcj nast npea ijvefj under a light pressarc 

{t) The net Area c4 tbc paaeagcfi tbrough tbc valves 
ahoald be grcai etKn^h to limit tbc TvJncitv at Aow througb 
tbem to 240 feet per minnie. 

(<r) The lift of the ralres sfaoold be snulL 

{d) The passage for ibe water sbonld be 3;s direit as 

(c) The valves mtist close tightly oodcr all cooditioas. 

(/) The valves and their seats most be durable and of 
such materials as are not easily affected by tfae impurities in 
the vater. 

ig) The valves must return to their seats quickly and 
without shock as soon as the current through them is stopped. 

(A) The valves and seats must be easily repaired or 
I removed when worn. 

I A great variety of valves have been designed with a view 

of satisfying these requtrem«at5, taking into consideration 
the widely varying conditions under which ptunps must 


I 14. T>f8k Talves. — ^Fig. Id shows two valves of a type 

■ 'P"^ used in alt classes of pumps for ordinary pressures and 

^^Hj^ service. The valve p 

^^^^B ^|fU consists of a vulcan- 

^^^^^^ nllln '^^^ India-rubber disk 

ihat rests f>n a gun- 
metal or brass seat s. 
The seal is threaded 
at /. so that it can be 
son-wed into the deck 
of the valve chamber 
and thus can be easily 
yd. The part 
r.f the pump chamber 
illed the valve deck. 

that cnntains the v 



§ 35 PUMPS. 9 

Qnd it is spoken of as the suction valve deck and delivery 
^alve deck in accordance with the kind of valves it carries. 
In the design shown at (a), the valve is fastened to a 
spindle ^ by a cap /. The spindle is guided by a cage- 
shaped guard ^ screwed on to the valve seat. The lower 
«nd of the spindle is made conical, so as to change the direc- 
tion of motion of the water gradually and to reduce the 
resistance to flow. In the design shown at (^), the spindle t? 
is screwed into the valve seat and carries a guard ^. A hel- 
ical spring between this guard and the plate /> helps to seat 
the valve quickly. 

The size of these valves varies from 2 to 6 inches in diam- 
eter, the most common size 
for ordinary conditions 
being 3 inches. 

16. When used for 

'Pip 'I'I 

pumping /ioi water, the 

disk must be made of a composition that will not be affected 
by the heat and for very high pressures metal disks are 
used, generally of the form shown in Fig. 11. 

16. Fig. 12 shows the construction of a large disk valve, 
such as is often used in mine pumps. The valve seat A is 
held in place by the flange B and is perforated, as shown in 
the top view of the seat, by a large number of small holes. 
The valve C is made of soft rubber and is placed within the 
bronze or composition cap D, The head of the bolt E forms 
a stop and the spring 5 assists the valve in closing. 

r7. Clack Valves. — A section of a clack valve is shown 
in Fig. 13. The clacks A and B are lined with leather 
on the bottom so as to make a tight fit on the seat without 
having to do much fitting. A stop C prevents the valves 
opening too far, while £ is the pin on which the clacks 
are hinged. A cylindrical casing Z^ forms the valve seat; 
it may be easily renewed when worn. These valves are of 
the type known as the butterfly valve, and are much used 
for pit pumps at mines on account of their cheapness and 
simplicity of construction. 

10 PUMPS. § 35 

18. Single-Settt ami Donble-ScAt TalTes.— A single- 
seat valve that is suitable for high pressures, up to heads 
of 500 feet, is shown in Fig. 14, where A is the valve; B is 

.(.liil \\\ih ilu' v;ilvf tint ids i-. i guide inside the 
/'; ;iii. I r. [■,(■. C art [ublur niit>'> which are kept 
[..n |.y imiiiis ..f ilu- -.tiiii iinl .ui. scp trated by the 



washers E, E, E. These rings prevent shtx-k as the valve 
lifts and also help to close it quickly, thus serving the same 
purpose as the helical spring in Fig. 10 {b). 

v\a. i& via. u. 

19, A section of a Cornish double-seat valve is shown 
n Fig. 15. This valve gives excellent results when used in 

large pumps working under high pressures and has been 
applied to pumps working under heads up to 700 feet. It 
is called a double-seat valve because it has two seats and two 




openings for discharge. The casing A slides on the vertical 
stem /i, its lift being regulated by the nut and washer A; 
when down, it rests on the valve seats C and D. When the 
pressure below becomes greater than that above, it raises 
the casing, and the water is discharged through the circular 
openings at t" and /). The rib around the outside of the 
casing is for the purpose of strengthening it. The valve 
seats are conical. The figure shows that one opening dis- 
charges the water under the lower edge of the valve and 
the other through the inside. 

20. wing Valves.— The Tvlng valve shown in Fig. 16 {«) 
is largely used in power pumps for feeding boilers and in 

hydraulic pumps for high pressures. The valve and sea^ 

e made either of hard brass or of gun metal and are ground 

I together to secure tight closing. The lower portion of the 

■■wings is sometimes curved as shown at 0), the object being 

to give the valve a partial rotation at each stroke of the 

pump. This compels it to seat at a new place with each 

stroke and tends to wear the valve and seat more evejily. 

31. Pot Talves. — Fig. 17 (it) is a sectional view of a pot 
valve. This type of valve is used principally on mining 
pumps for lifts up to 1,000 feet. They are made separate 
from the pump chambers and may be readily replaced when 
broken or worn. The cover a is secured by hinged bolts, so 
that it may be quickly removed for access to the valve i* and 
the valve seat c, which is made of composition and pinched 




between the pot and the pump chambers. The valve 
spring d surrounds the valve guide e. 

38. Fig. 17 (*) shows a type of pot valve used for high 
lifts up to 1,200 feet. The valves are made small and faced 
with hard rubber; a group of them is placed in one heavy 

pot which is bolted to the pump chamber. Access to the 
valves may be had by removing the cover «. The valve 
seats are made of composition bushings forced into the 
valve deck 6. 



23. Even in double-acting pumps there is an interntp- 
tion of the flow at the end of the stroke, when the piston 
changes its direction of motion. This has the effect of 
bringing the column of water in the suction and discharge 
pipes to rest at the end of each stroke, and this column of 
water must be set in motion again as the next stroke is 
made. If the pipes are long, the force required to stop and 
start the water will be very great, and there will be a severe 
shock at the end of every stroke that will absorb power and 
subject the pump and pipes tn great stresses. 




This difficulty is removed and the flow through the pipes 
is made more continuous and steady by the use of air cham- 
bers. An air chamber is a vessel containing air and is 
attached either to the pump just outside of the discharge 
valves or to the discharge pipe near the pump. While 
small duplex pumps are often nm without an air chamber, 
it is better in general to fit one to all puraps, since its 
effect will always be beneficial. 

DE1,1\-Eliy Aril CHAMBERS. 

24. Principle of Action. — Fig. 18, which shows an air 
chamber attached to tin; discharge pipe of a single-acting 

§ 35 PUMPS. 15 

drawn in through the pipe / past the valve g^ is forced by 
the plunger c past the. valve // into the discharge pipe a^ 
part of it flowing into the air chamber b and compressing 
the air therein. When the plunger reaches the end of its 
stroke and no more water is being forced into the discharge 
pipe, the compressed air in the air chamber forces the extra 
water out through the discharge pipe. In this way the air 
chamber acts as a reservoir that receives its supply during 
the inward motion of the plunger and gives it out again in 
a nearly steady stream. The air in the air chamber acts as 
a spring that absorbs the extra force during the inward 
stroke of the plunger and gives it out during the return 
stroke, thus relieving the pump and pipe of shocks and pro- 
viding a nearly constant rate of flow from the discharge. 

26. Size of Delivery Air Chamber. — The proper size 
of an air chamber depends on the type of pump, the speed 
at which it works, the length of the discharge pipe, and the 
pressure head against which the pump works. For ordinary 
double-acting pumps working against moderate pressures 
and at ordinary speeds, the cubical contents of the air 
chamber should be not less than 3 times the piston displace- 
ment. For pressures of 100 pounds per square inch and 
upwards or for high piston speeds (as in the case of fire 
pumps), the capacity of the air chamber should be at least 
6 times the volume of the piston displacement for a single 

36. LiOSSofAir. — Under the increased pressure in the 
air chamber, the air is absorbed by the water and gradually 
passes off with it. In this way all the air will finally pass 
off and the chamber will be made useless if no means are 
provided for renewing the supply. 

!87, A simple device for maintaining the supply of air in 
the air chamber of large pumps is shown in Fig. 19. A 
piece of 2i-inch wrought-iron pipe c about 30 inches long is 
connected to the end of the pump cylinder a in a vertical 

H. S, v.— 7 




position, by means of a gat« valve i. or cock. A 3^-tnch T</ 
at the upper end of this pipe is connected at one end 
_ of the run with a 
l^inch check-valve r 
opening inwards, and 
_f^\ rf, lil at the other end with 

^^"^^Wr-^— ^K>^°^<lLv'=^ a J-inch check-valve/ 
~}W' JtllXX IL ' iViy that opens outwards. 
"^-^^ Y V ^^-^-^J-^ The valve / is coa. 

necied with the ai^ 
chamber through thA 

This air pump is 
operated as follows: 
When the pump is 
working, open the 
valve i to fill the 
pipe c with water; 
then partially closed' 
until the checb^ 
valves c and / begiK 
to work. This 
easily determined by. 
^'"^ '** the click of the valves 

when seating. Its working maybe described thus; When 
the valve i is opened, water fills the pipe c from the 
pump cylinder a during the discharge stroke of the pump. 
By partly closing d when c is full, the pump during 
the suction stroke will draw a part of the water from c. 
and air will flow in through *■ to take its place. During 
the next discharge stroke of the pump, more water 
forced into r, driving the air out through / and ^ 
the air chamber. If ii is opened too wide, all the wati 
will be drawn out of c during the suction stroke 
air will be drawn into the pump cylinder from e; but by 
pro|K;rly regulating the opening, a column of water is kept 
in c, which acts as a piston that moves with the strokes 
of the pump and pumps air into the air chamber. 

ir IS 




38. Allt'vliitor. — When pumps work under pressures 
greater than that due to a 350-fooi lift, air chambers are 
not of very much service, owing to the 
(act that the air escapes from the air 
chambers either through the pores of 
the iron or at the Joints, or it is absorbed 
and carried off by the water; in such a 
condition an air chamber gives the 
pump no relief whatever. To obviate 
this defect alleviators are used. An 
alleviator is shown in Fig. 30. It con- 
sists of a plunger a working through a 
water-packed stuffingbox. On top of the 
plunger are arrangtfd springs that may be 
in the form of rubber buffers or helical 
coil springs. In the type shown rubber 
buffers 6, 6 are used, which are confined 
by the tie-rods c, c, the yoke </, and 
the plates f, c. When the pressure in the 

■:pipe exceeds the working pressure, the 
plunger a is forced out through the stuf- 
fingbox and relieves the pump of the ''"'■ *"" 
shocks that would otherwise occur. Alleviators may be 
placed anywhere on the delivery pipe, but are preferably 
placed in such a position that the direction of the moving 
water is in line with the plunger a. 


29. Purpose. — With a long suction pipe or a pipe with 
"numerous bends and valves, the resistance to the flow of 
the water through it will be considerable, and a great deal 
[ force will be required to start and stop the water in it 
*ith each stroke of the pump. In some cases the force 
fequired is so great that the pressure of the atmosphere is 
tot sufficient to set the column of water in motion quickly 
Enough to fill the pump chamber as fast as the piston moves. 
This makes the action of the pump imperfect and causes a 




severe lilnw, called the -wnter hammer, when the piston 
again meets the inflowing water. 

30. The difficulty mentioned in Art. 29 can best be 
remedied by the use of a chamber, called a vacuum cham- 
ber or a suction air chamber, attached to the suction 
pipe as near the pump as possible. In its general form a 
vacuum chamber resembles an air chamber, but the pressure 
in it instead of being greater is always less than the atmos- 
pheric pressure. When the pump is drawing water, the air 
in the vaciuim chamber expands and forces the water below 
it into the pump; at the same time the pressure of the 
atmosphere forces water in through the suction pipe to 
balance the reduced pressure in the vacuum chamber. The 
vacuum chamber is again partly filled and the air in it is 
compressed during the discharge stroke of the pump. It 
thus acts as a reservoir that receives from the suction pipe 
a nearly steady supply, which is given up intermittently to 
the pump. 

31. Special Form of Suction Air Chamber.— Fig. 21 

shows a special form of a suction air chamber in diagram- 

matic form. The suction pijie a connects to a 
chamber b, which has a lube c projecting downwards 

suitable ^H 
wards to ^^| 

§ 35 PUMPS. 19 

within a short distance of the bottom. The tube f, which 
is called a draft tube, connects to the pump chamber. 
When water first flows into the chamber b^ it entraps some 
of the air as soon as the water seals the bottom of the draft 
tube ; this air is then compressed while the water flows up 
the draft tube, and by its expansion and compression per- 
mits a steady flow in the suction pipe. 

32. Size of Vacuum Chambers. — For ordinary cases, 
the vacuum chamber may be made half the size of an air 
chamber working under the same conditions. A good rule 
is to make the cubic capacity of the vacuum chamber for a 
single pump twice that of the displacement of the piston 
for a single stroke. 

33. liocatlon. — Suction and delivery air chambers 
should, if possible, be placed at a bend in the pipe and close 
to the pump and in such a position as to be in line with the 
flow of water in the pipe. If placed at right angles to the 
flow of water, as in Fig. 18, their efficiency is somewhat 
impaired. Both suction and delivery air chambers should be 
provided with glass water gauges so that the height of the 
water can be determined at a glance. It is not customary 
to provide the air chambers of small pumps with water 

PUMP foundatio:n^s. 


34. The foundation for pumping machinery depends 
entirely on the type of pump. Generally speaking, much 
less foundation is required than for steam engines occupying 
about the same space. Direct-acting duplex pumps probably 
require the least foundation of any kind of steam pump, for 
here the piston and plunger motion is almost opposite and 
the balancing of the machine in line with the plunger motion 
is complete, and the strains due to reversing are contained 
almost wholly within the machine itself. Small duplex- 
pump foundations are made of a solid mass of brick or 

PUMPS. § Sft 

concrete, while large piiinps are often set on separate piers, 
one for the water ends and one for each pair of steam ends in 
case of a duplex, compound, or triple-expansion engine. Of 
course, the foundations must go down to sufficiently hard 
soil to bear up the weight of the pump, or if the soil be loose 
sand or gravel, the foundation must be spread out sufficiently 
to insure the pressure not exceeding, say, 1 ton per square 
foot. The foundation should go deep enough to allow the 
surrounding soil sufficient hold upon it to keep it firm and 
steady. The minimum depth for a small pump should not 
be less than 2 feet. Single-cylinder pumps require a some- 
what heavier foundation than duplex pumps, owing to the 
greater shocks to which they are subjected, 

35. Crank-and-fly wheel pumps require considerably more 
foundation than direct-acting machines, on account of the 
much higher speeds possible and the weight and lack of 
balance of the reciprocating parts. Crank-and-flywheel 
pumps of the control led -valve type, as the Riedler pumps, 
which usually run at a high speed, require foundations fully 
as heavy as those for steam engines of equal size. 


30. Foundations should be built of hard brick laid in 
cement mortar, concrete, or, in the case of large pumps, of 
stone, if it can be readily secured. All pumps should be 
held down by foundation bolts. In the case of small pumps 
the bolts are provided with a steel or wrought-iron plate 
washer built solidly into the foundation, while large pumps 
have tunnels or pockets for access to the lower foundation 
washer and nut. If the foundation bolts are built in solid, 
box washers should be used. 



37. In the case of large vertical pumping engines, the-n 
masonry required to form the pump pit and to support th« | 
superstructure is of ample mass for all foundation purposes; J 
in fact, large arched chambers and tunnels are often used to ] 

§ 35 PUMPS. 21 

Save foundation materials in this class of pumping engine. 

These large pumping engines are often located at or near 

a. water supply where the soil has not sufficient rigidity to 

support the weight. In this case piling must be resorted to, 

on which the foundation proper is constructed. 


38, A foundation templet should always be used in 
'which the foundation-bolt holes are carefully laid off, prefer- 
ably from the actual castings, and the various heights of 
bosses or thicknesses of casting through which the bolts pass 
are marked. The templet should be carefully set with 
reference to the suction and delivery connections, so that 
when the pump is set up, the fittings and pipes will connect 
up properly. In large pumps it is customary to arrange 
the pipe connections in such a way that a short space is left 
between the piping and the pump. This space is then 
measured after the pump and piping are in place, and a dis- 
tance piece is made to suit the measurement and then put 
in place. 


39. Small pumps of the single-cylinder and duplex type 
are usually provided with two points of support only, one 
of which is rigidly bolted to the foundation, while the other 
is left free. This prevents the pump being thrown out of 
line, if properly constructed originally. When both the 
steam and water ends are bolted down, care must be taken 
not to twist or throw the pump out of line. In making the 
steam and water connections, the pipes should come fair to 
their connections and should not be sprung into place. 
Stresses on the pump structure due to winding foundation 
surfaces and sprung pipe connections should be guarded 
against, particularly with steam-thrown valves, as these are 
very sensitive and must be perfectly free. Any slight 
springing of the valve chamber will bind the valve and pre- 
vent its operating. 

srcTioN riPiXG. 

40. Loc«tiaa of Pump In Re^peot to Supply. — Before 
a pump can be properly IolmiihI, Lhe tcicaijon of the source oX 
supply of tbc liquid to be pumped must be taken into consider — 
aiton. Since the atmosptKric pressure of 14. 7 pounds to the' 
square inch vitl balance a column of water 34 feet high, it is 
evident that with that atmospberic pressure the pump musC 
not be placed more than 34 feei vertically above the surface 
of the water to be pumped. But since 3 perfect vacuum 
canmit be obtained by mechanical meaos. and since the flow 
of the water is retarded by frictic>n in the pipes and passages, 
the limit of vertical lift by atmospheric pressure is reduced 
to about liR feet at sea level in actual practice. The actual 
lift, precisely as the theoretical lift, varies with the atmos- 
pheric pressure, and hence will become smaller with an 
increase f>f altitude above sea level, since the air becomes 
lighter and its pressure less. 

41. Run orSuetion Pipe.— The pump should be placed 
as near the source of water to l>e pumped as is possible, both 
vertically and horizontally. The suction pipe should be as 
straight as p<.iissiblc: if bends are necessary, tbey should be 
made by bending the pipe to a long radius or by using long- 
turn fittings. The suction pipe should be one diameter 
from end to end ; all enlargements or reductions in size tend 
to disturb the uniform flow of tits water so essential to a 
proper filling of the pump chamber. If from necessity the 
inictian pipe is very long, it will be well to increase the siie 
MUQewbat ; the reduction at the pump chamber should then 
be made by a long conical fitting. For ordinary service 
pvURps the diameter of the suction pipe should be such that 

velocity docs not exceed 200 feet per minute, assuming 

the Bow of water is constant. If the vertical lift be 

suction air chamber should be pro%*idcd: this will 

§ 35 PUMPS. 23 

3.dd much to the uniformity of the pump supply. A foot- 
Valve should also be provided when the lift is high. 

43. Foot- Valves. — A foot-valve is a check-valve placed 
a.t the lower end of the suction pipe below the water level 
in the source of supply and opening towards the pump. Its 
purpose is to prevent the suction pipe emptying while the 
pump is at rest and to prevent the water in the suction pipe 
slipping back while running. When the water flows to the 
pump by gravity, a foot-valve is superfluous; but when the 
water is lifted by suction it is often fitted, since it will insure 
a prompt starting of the pump, providing that it is tight 
enough to hold the water in the suction pipe. In very cold 
weather and in exposed locations, the foot-valve constitutes 
an element of danger when the pump is out of use, since it 
prevents the emptying of the suction pipe. The water in the 
latter may freeze and burst the pipe. To prevent this, a 
drain may advantageously be fitted to the lower end of the 
suction pipe, which is used in cold weather to empty the 
pipe if the pump is to stand idle for a long time. 

43, When foot-valves are used, a relief valve may 
advantageously be placed on the suction pipe. Generally, 
the suction pipe is made considerably lighter than other 
parts of the pump, and if the suction valves should leak 
when the pump is standing or if the priming pipe be left 
open, the full pressure of the delivery water will come on 
the suction pipe and foot-valve, which are not usually 
designed to withstand such pressures. The relief valve, 
which should be set to relieve the pipe at a pressure well 
within its safe strength, prevents overstraining of the suc- 
tion pipe from this cause. Foot-valves should be chosen 
with the greatest care; they should be simple and, prefer- 
ably, of the weighted-lift type or clack valve, and should 
have at least 50 per cent, excess of area over the suction 

44, Settlinic Chamber. — If the water to be pumped is 
gritty or contains foreign substances, a settling chamber is 
sometimes used, especially when pumping water holding but 

S4 PUMPS. g 35 

a small quantity iif sand in suspension. This consists uf an 
iron box conveniently arranged in a horizontal pipe. It is 
usually of large relative capacity, a settling chamber for a 
2-inch pipe being 3 feet X 'i feet X 3 feet long. The pipes 
enter and leave from opposite sides and near the top. The 
increased volume of the large box allows the water to move 
very slowly across the box, giving the suspended sand time 
to settle to the bottom. The settling chamber should have 
a removable cover for the purpose of removing the settlings. 
This device is used on small pumps working on artesian 

4J). P^iictlon Ilasket and Htralnei*. — More universal 
arrangements for keeping back foreign matter from the 
working barrel of the pump are the suction basket 
and the strainer. The suction basket is usually placed 
on the bottom of the suction pipe and consists of a 
box variously shaped and perforated with strainer holes 
or provided with screens. The suction basket so placed 
is being replaced by a different form of strainer, which 
consists of a chamber placed in the suction pipe, located 
in an accessible position and provided with strainer plates 
so made that they can be readily removed for clean- 
ing. This strainer is sometimes connected directly to the 
pump, but it should not be so placed that it will inter- 
fere with removing the water-cylinder heads. A short piece 
of pipe between the strainer and pump nozzle will avoid 
this interference. The objection to the suction basket on 
the bottom of the suction pipe is its inaccessibility for clean, 
ing and inspection, a feature that is overcome by tha, 


46. Run and Valves. — While the suction pipe is very 
important and must be most carefully laid out and has mnch 
to do with the location of the pump, the delivery pipe should 
not be neglected. A careful adjustment between the supply 
and delivery pipes should be made in order to prodi 


I produce thi;^! 




§35 PUMPS. 25 

best effect of the whole plant. The delivery pipe should as 

^ar as possible be a plain, straight pipe from pump to ter- 

'ninal; when bends are necessary, they should be by as long 

sweeps as possible. A gate valve or check- valve should be 

placed near the pump. The check-valve serves the double 

purpose of relieving the pump of pressure when starting 

^P, allowing it to take hold of the water more quickly, and 

^1^0 holds the water back from the pump when inspection 

^^d repairs to the water end are necessary. If a check- 

^^Ive is not used, a gate valve should be placed at or near 

^*>e pump delivery to hold back the water in case of repairs 

^^^ the pump end or accident. This valve should always be 

^ straightway gate valve giving the full clear opening of 

^l>e pipe. 

47. Velocity of Flow. — The velocity of the water flow- 

^^g through the delivery pipe for direct-acting pumps should 

^ot much exceed 330 feet per minute, while for large crank- 

^nd-fly wheel pumping engines the velocity of water in both 

Auction and delivery pipes is about 300 feet per minute. If 

^he suction pipe is made small, the pump will fail to fill and 

t:he plunger will strike the incoming water on its return 

stroke, producing a violent and dangerous shock. If the 

delivery pipe is made small, the cost of power required to 

force the water through the pipes at a high velocity will 

very quickly overrun the interest and depreciation on a 

larger pipe. 



48. Water-End By-Pass. — By-pass pipes are pipe con- 
nections from above to below the delivery-valve deck and are 
of much more use on crank-and-flywheel pumps than on 
direct-acting machines. In the case of compound pumps, 
when starting up, the force of the full steam pressure on the 
high-pressure piston is not sufficient to move the plungers 

iO PUMPS. g35 

.-i^aiiiiit the resisiani-e due to the head of the water in the 
dcli\*«:ry piiw; hut l>y opeiiin({ the valve (which, liy thcwa}'. 
should always be a gale vatve) in the by-pass piping, the pre*- 
surcoR the plungers is relieved for a sufficient number t:*^ 
strokes ti> allow the steam to reach the low-pressure pistoK^' 
when the combined force of the two pistons will do the wor" '^ 
and the by-pass piinr ran l«e closed. 

49. By-pass water pipes liave another function on crant— •*^" 
iind-flywheel pumi>s. Unless these machines are fitted wii ^ 
very large flywheels, their limit to sltiw running is often nc^:^^'^ 
as low as ilesired. By opening the valve in the by-pass pipe^^' 
part of the water can Iw returned to the pump chamber aiic^ " 
the amount of water .icliially pumped reduced to any desirec:^ 
i)uantity permitted by the size of the by-pass. It should no^ '^ 
beoverKwked that lhisi» accomplished at a very considerabli^^^^^ 
loKS of efficiency, because it takes the same power to niove^^* 
the, by-pass water as it does to do the actual pumping, com- — "^ 
IKtring equal i)Uantiiies. By-pass pipes are usually made "^^ 
3i per cent, of the plunger area. ^^ 

30, Htwini-Kiicl ».v-Piie*i — -It is common practice to fit ^| 
the steam cylinders with by-pass pipes, allowing high-pres- ^M 
sure steam to act on the low-pressure piston in starting. 
but these pipes are usually so small, compared with the 
diameti-r of the li>w-pressure piston, that the by-i>ass is 
unable to hold any pressure behind the low-pressure piston 
when it is mnving. By-pass steam pipes have their proper 
nst' in w:iniiinj4 up the low-pressure cylinder and connections, 
,iiiil ill [111' I ;i-.i' .it iT.vnk-and-flywheel pumps to move the J 

liiilli 11H--II1. . r..iik .'ff tin- dead center. I 

■Iiili-kIok plpo is a small pipe run 
yond the check-valve or delivery 
chamber of the pump. It is par- 
se of long suction lifts to fill the 
lion pipe with water, taking up all 

§ 35 PUMPS. 27 

clearances and helping the pump to take hold of the water 
quickly. This pipe may be from f of 1 per cent, to 1 per 
cent, of the area of the plunger; its size is a matter of little 
importance, but it should be large enough to fill the suction 
pipe and pump chamber in a reasonable time, which will 
depend somewhat on the size and design of the pump 
chamber and the length of suction pipe. A pipe much 
larger than 1 per cent., of the plunger area will be required 
in the case of long inclined or horizontal suction pipes. 


63, A waste delivery or startini? pipe that can be led 
into any convenient place of overflow should be provided so 
that the pump, in starting, can free itself of air, for it often 
happens that a pump refuses to lift while the full pressure 
against which it is expected to work is resting on the delivery 
valves, for the reason that the air within the pump chamber 
is not dislodged but only compressed and expanded again by 
the motion of the plunger. A pump in this condition is said 
to be air bound. It is well in this case to run with the 
delivery pipe empty until the air is expelled and the water 
flows into the suction end of the pump. The waste delivery 
pipe is fitted with a valve and connected to the delivery pipe 
close to the pump. When the water flows to the pump and 
is discharged into the delivery pipe, the valve in the waste 
delivery pipe is to be closed. 


63. When a check- valve is not used in the delivery pipe 
and the space between the suction and delivery valves is 
large and the delivery pipe is full of water, the pump will 
often refuse to start the water in the suction end, owing to 
compressed air being trapped between the water in the 
delivery pipe and the delivery valves. Air discharge valves 
performing similar service to the waste delivery or starting 



pipes may then be used to allow the compressed air to escape 
and a vacuum to be created when the plunger is withdravn 
frum the pump chamber. In small pumpsof the direct-act- 
ing type, a petciock is usually 6lted for this purpose to the 
co*-er cUrcciIy above the delivery valves. 


54. Fig. ti sbowsa good arrangement of a pump in reia- 
tioa to the water supply and of the pipe connections. The 

with ihc foot-valve d and has a 
» the pinnp. from which it is scpa- 
e piece J. When the vertical lift is 
a and the pump is placed close to 
rtk>n air chamber is seldom neces- 
t exceeds lu feet or when the pump is 

§ 35 PUMPS. 29 

at some distance from the water supply, a suction air 
chamber becomes a necessity. With a vertical suction pipe 
as shown, the suction air chamber may be made as shown by 
the dotted lines at c. An air chamber f\s placed on the 
delivery between the delivery check-valve g and the delivery 
valves. The waste delivery or starting pipe i is connected 
to the delivery between the delivery valves and the delivery 
check-valve g. It is fitted with the valve k. The delivery 
pipe // is connected to the suction pipe close to the pump, in 
this case to the distance piece d^ by the priming pipe /, 
which is fifted with the stop- valve ;;/. 


56. Proper drain pipes and drain valves should be pro- 
vided for all parts of the pump, the pipe connections, 
strainers, etc., in short, for all parts in which water may 
remain when the pump is not in use and will give trouble 
by freezing. 

Provision for draining the suction valve deck and delivery 
valve deck is sometimes made by drilling a small hole 
through the decks; this practice, while simple and cheap, 
leads to a loss in efficiency, however, since some of the 
water is constantly flowing back into the suction chamber. 



66, If a pump has been properly selected for the service 
and has been properly designed, built, and erected, it should 
perform its work without any trouble. All pumps when 
new are stiff and cranky in their actions, particularly direct- 
acting pumps. They should be run slowly for a considerable 
time, and many defects in their action which at first gives 
rise to alarm will then gradually disappear. Crank-and- 
flywheel pumps act more smoothly from the start, but do 

30 PUMPS. § 35 

not come to a proper bearing more quickly or quite as quickly 
as the direct-acting pump. Crank-and-flywheel pumps usu- 
ally require considerable skill and study to reduce them to 
successful working order, as conditions arise that further 
disturb the lack of harmony between the flywheel and water, 
and it often taxes the skill of the experienced engineer to 
make an amicable adjustment between the two opposing 
forces. • 

67. Having reduced the pump to satisfactory operation, 
the attention of the operator should be directed to its main- 
tenance at the least possible expenditure. Each item of 
expenditure should be separated from the whole and studied 
independently for the purpose of reducing it to a minimum 
consistent with the proper maintenance of the plant. The 
expenditure should at all times be regarded as the item by 
which interest or dividends are being earned and should not 
be allowed to become greater. 

58. Losses in elliciency arise from wear, from loss of 
proj)cr adjustments, and from the wrong timing of the vari- 
ous movements that control the distribution of steam, by 
leakages, by decreased mechanical efficiency due to lack of 
alinement, by accumulations of foreign matter on and in 
coiulensor lubes, suction strainer, and foot-valves, suction 
and tlciivcry i)ipes, antl in many minor directions. In many 
plants it is of the utmost importance that they should not 
1)0 interruj)te(l ; it is then the duty of the engineer to predict 
all |)ossil)lc events that might cause an interruption and 
have a well-])lannecl line of action prepared so that he may 
act (juickly aiul with decision to the end of keeping his plant 
always at work and at the highest efficiency. This plan of 
action will entail considerable work, study, and, perhaps, 
st)nie expense in preparation to meet possible contingencies 
that may never hapj)en: nevertheless, it is well to be ready 
for any emergency when handling steam machinery and 
particularly steam pumping engines. 

i>l). In the management of pumps it must be considered 
that nearly every installation has its peculiarities, some of 


§ 35 PUMPS. 31 

which are sometimes not discovered until after the machine 
is put in service and then perhaps require expensive addi- 
tions and alterations to meet them. An exhaustive study 
of existing conditions and resultant conditions when the 
pump starts to work cannot be too strongly urged. 



60. Pumps differ so much in their construction and 
design that it is entirely impossible to lay down specific 
rules that will be applicable to every pump. For this reason 
only general rules are here given, which must be modified 
by the pump attendant to suit every specific case. 


61. Gettingr Up Steam. — Considering a new steam 
pump, after it has been properly erected on a suitable foun- 
dation and all the pipe connections have been made, the 
first step in starting the pump is to get up steam in the 
boiler or boilers in the same manner as is done with boilers 
supplying steam for any other purpose. 

6S« Since the boilers are generally in charge of the same 
person that attends the pump, the general treatment of the 
pump and the boilers, while steam is being raised, will be 
considered together. After the steam piping is in place, 
but before it is finally connected to the pump, all valves in 
it should be opened wide; while steam is being raised the 
pistons .and valves should be removed from the steam end 
of tlie pump so that there is a clear passage for the steam 
froin the boiler to the exhaust after the steam pipe has been 
connected to the pump. 

lb. 63» Blowlngr Ont the Steam Piplnpr. — The fires should 
\ Started very slowly under the boiler; all the binding 

33 PUMP& § 35 

lK>Its thron$:hout the boiler setting should be perfectly loose 
and free. It this precaution is neglected, buckstaves or 
cast-iron fronts will be broken by the expansion of the set- 
tins:. The guy nxis on iron stacks should also be slacked 
off: in fact, every part that vill expand when the plant is 
started up should be liberated. Before the steaming stage 
is reaoheiL large volumes of heated air will be driven through 
the pi|^s. warming them up gradually. When steam begins 
to rise, it should be allowed to blow through the piping and 
valves quite lilnrrally, the object being to dear the piping of 
s:uu1. grit« and all other foreign matter collected therein 
during erection. The piping having been blown out 
thoroughly, steam is shut off and the piping is then con- 
nected to the pump. 

iV4. lUowlnirOtit the Cylinder. — ^Whenthe pressure in 

the boiler has l>een raised to the working pressure, the cylin- 
der heads shiuild Ix" put on, still leaving the pistons and 
valves out ot the cylinders. The stuffingboxes should be 
cU^seil, which is most conveniently done by placing a piece 
of luKird iH'tween the stutRnglK^x and the reversed gland 
and then setting up the nut on thestuffingbox studs. When 
the glaiul is drawn home by a nut outside of it, a circular 
piece t>t pine Inurd may l»e placeii between the end of the 
glanil anil the inside of the nut in order to close the open- 
ing through which the piston nni jxisses. The Steam may 
now be turned on tlie main steam pijx* leading to the pump; 
l>y opctviv.^v i],^. ihroitle valve wide at short intervals, the 
Sara! a:^.l >so.i\ :-. the ptTts and other passages and spaces of 
uw <ir.rr.: r-..: vm:i i^- Mown out. After the cvlinders have 
I'Cfn !l'\v. .-r.:. liu' heads and covers sh«»uld be removed, and 
all :'M-»'ii::-. ir.attrr M.»wn int«> the corners and chambers of 
tile i'\!i!ukr< >h »uld be removed by hand. The pistons, 
valvr>, cvr.ndtr heads, and other covers can now be put in 

CJ.^. T'r.f I-;, .wing <'ut of the i^'pes and cylinders after 
creition i> ..fien neglected or but imperfectly done, with 

§ 35 PUMPS. 33 

serious consequences to the machine; it cannot be too thor- 
oughly done, particularly in that type of pump where the 
steam ports and exhaust ports are on top, for in this particu- 
lar case the sand and grit are deposited in the bottom of the 
cylinder for the piston to ride upon. If more attention 
were paid to the thorough cleaning of all steam spaces, we 
would hear less of cylinders and pistons being cut. 

66. Keying Up. — If the pump is of the crank-and- 
flywheel type, it should be turned a complete revolution by 
hand to insure that everything clears properly and that no 
tools or materials used during construction or erection have 
been left within the machine. The adjustment of all jour- 
nals, pins, and bearings should then be made. With gib 
and key ends, it is usual to drive down the key with a soft 
hammer (lead hammer) until it is home, mark it, drive it 
back, and then tap it down to within ^ inch of the mark. 
With wedge ends the wedges usually have an inclination of 
H inches per foot and the adjusting screw 8 threads per inch. 
The wedge is drawn up solid and then the adjusting screw 
is turned back about 20° and locked. Bolted connecting- 
rod ends are allowed about -^i^ inch play, using liners and set- 
ting the bolts up solid. Main bearings can be adjusted best 
when the machine is in motion. 

67. Packing Kods and Stems. — The packing of all rods 
and stems is the next step. If fibrous packing is used, the 
boxes should be filled full and the glands tightened down 
very moderately. The tightening of the glands can best 
be done when steam is on and the machine is in motion, 
when they should be tightened only sufiirient to stop leak- 
age and no more. When excessive tightening is required to 
stop leakage, the packing should be completely renewed. 
Some pumps are fitted with metallic j)ackings. These 
packings are usually fitted up by specialists who fully guar- 
antee them, and their directions for use should be carefully 
followed; in case of failure or unsatisfactory results, the 
makers should be consulted. 

68. Olllnsr.— The oiling of the machinery is the next 
step and Is a very im[K)rtant one. All rubbing surfaces 
should be provided with suitable oiling devices appropriate 
to the particular place and service. The quality of oil 
should be carefully selected to suit the velocity and pressure 
of the rubbing surfaces on which it is used. For use within 
the steam cylinder, heavy mineral oil is the only oil capable 
of withstanding the high temperature, and in starting up 
new pumps only, the best quality should be used, regardless 
of price. A liberal use of this oil for the first month will go 
far towards reducing subsequent oil bills. 

69. The pumping engine, unlike many other types of 
engines, must often run continuously and without interrup- 
tion for a month or even longer at a run. This requires 
that all oiling devices be so arranged that they can be sup- 
plied and adjusted while the machine is in motion. It is a 
good plan to provide two separate sets of oiling systems for 
ail the principal journals, the idea being that if one fails the 
other can be used while the disabled one is being over- 
hauled. All oil holes should have been filled with wooden 
plugs, bits of waste twisted in the hole, or some other pro- 
tection, while the machine was being erected. These should 
now all be removed and ail oil holes and oil channel thor- 
oughly cleaned out. Bearings should be flooded with oil at 
first to wash out any dust or grit that may have reached 
the rubbing surfaces. 

70. Having turned the machine by hand and inspected 
all locknuts, setscrews, and clamp screws, the engine may 
be put under steam. If provided with hand starting gear, 
this should be used for a sufficient number of turns to make 
sure that the machine is free from water that may have 
accumulated in the pipes or clearance spaces. All drain 
cocks should be wide open when starting and relief valves 
should be adjusted to blow at the proper pressure. If the 
engine is condensing, connections from the exhaust port to 
the condenser should be made absnhitely tight. If an 
independent condenser is used, it should be started before 

§ 35 PUMPS. 35 

the main pump is started and a vacuum obtained in 

71. So far only the steam end of a large crank-and-fly- 
wheel pump has been considered. With the direct-acting 
single or duplex steam pump, the same general method of 
procedure should be followed. It may be mentioned here, 
incidentally, that the direct-acting pump is not so liable to 
an accident in starting as the crank-and-flywheel pump on 
account of the absence of kinetic energy stored up in a 
moving flywheel. This energy when given out by reason of 
an obstruction in the water end that prevents the free pas- 
sage of water will greatly increase the pressure, especially 
when the obstruction occurs near the dead-center positions 
of the crank. The increased pressure thus produced may 
easily run up high enough to burst the water end. 

72. Using the Dash Relief Valves. — In starting a 
direct-acting pump when dash relief valves are fitted, they 
should be closed in order to keep the pistons as far from the 
heads as possible, for in new installations the unexpected is 
likely to happen at the water end, and to prevent danger of 
a breakdown, as in case of a sudden lunge of the pistons, all 
the margin possible to keep them from striking the heads 
should be gained. 

73. Condition of Water End When Starting:. — Assu- 
ming that the plungers and plunger rods are packed and the 
plunger grease cups filled, the water end should be ready to 
start; if the machine is compound or triple-expansion, the 
water by-pass valves must be opened until the machine has 
made a sufficient number of strokes to bring the intermedi- 
ate and low-pressure cylinders into action, when the by-pass 
valves should be closed. The suction pipe from the foot- 
valves to the delivery valve deck must be absolutely tight; 
anything short of this will cause the water end to refuse to 
work satisfactorily. All the suction valves and delivery 
valves should seat fairly and tightly. Care must be taken 
that there is no obstruction in the delivery pipe, such as a 

' 1 <of valTe. 2.f 7 -^:l'^ "^i^'.'.y have sufficient margin in the 
•:r.v:r.^; f ric v-rr :r.T rT^ t :• ^ur-^t the water end, 
par': ulirly :: :r.c n: ni'rr.tun: •: : a ty wheel be added to it. 

#-l. l*rr>^iTr ;^-au^-r> >h' ul'i alwavs be attached to the 

^•;- :: r. ar. : i-riivrry p:p«es. ar.«i they should be carefully 
witoh^rl ^iurir.;^ the ir-:e>> •.f starting:. a5 trouble at the 
water irr.'i w:!l *:.*: pr -mptly rr»: -rded by the gauges. The 
I'.wer er.'i ■ : thrr su'iti- r. p:r«: sh'.uld be kept well under 
witrr. a-i a >!j^' ■-: air takrr. int' the pump may cause a 
v: Irr.t jump-.r.;^ and in a dire*:* -acting pump possibly a 
striking: f the strram pist'^ns aicain-i: the heads. 

75. Watching the Air Chamber. — The delivery air 

chamV_r -h jM ^<: . arefully watched during the starting 
ar.'i Th:> -h'-jld 'ce pr-vidcd with a gauge glass 
>h .wir.'C th- h-::^'ht ••:' the water and extent of the pulsation. 
Th',- air '.ham'' ^ r >h -jM Zf^ «:harj^*rd with air when the air in 
the chamber is ! -t. a- sh-wn *:-y the rise of the water in the 
;/a::^e ^la>s. Laricr.- pumps are usually supplied with an air 
•\r:ri-z pump that is attached t • and driven by the main 
p>ump. • r an arranij^emerit 'A pipes and valves is sometimes 
impr-'vi-ed f -r this nurix'Se. In very large pumping plants, 
an'rnt air •: 'mpress-.-r --r 1 «c« 'motive air pump is 
''ften u-ed I'-r this -^vrvice. A verv i^-xi idea of the inter- 
:;:il W/rkin;^^ ■ t t::e pump can 'r-e •-': t^iined by placing the ear 
a;^^ain<t the pump • ham hers: the seating of the valves can 
th»n he 'ii-tir. t!y iieari. an ! i: there is any leak past either 
the suet: -r. • r ::>.- delivery va'.ve^. it, to<». is quite audible. 

I)KFF(T> IN IM'Mrs. 
^rr TH)V-KM> THoniLE'";. 

76. The iw -'. < -.nm.-.n cau>'-- • •: ■•u::!;) failures are leaks 

4 A 

below the >u' :: n valves. The>e may be at the joints or 
along the -u'ti'.n pipe ..r in tl:e pump chamber, and may 
be due to imp'-rfe«-t < -..nnect:- n>, leaky cliaplets, shifted 
cores, l^lo\vh'»i»-^. eMrrMsion. .-r . rai ks trum trust. 

§ 35 PUMPS. 37 

77. Small leaks in the suction end which are not suffi- 
cient to cause entire failure will cause the piston to jump, 
i. e., move suddenly, during the first part of the stroke. 
Leaky valves and plungers reduce the capacity of the pump; 
if this is the case, they should immediately be refitted and 
repacked. It is always best to have hot water flow to the 
pump by gravity; if it is necessary to lift it and the pump 
works with a jerky action, the lift is too high for the tem- 
perature, and one or the other must be reduced. In pump- 
ing from wells, care should be taken that the pump is near 
enough to the water to prevent the water falling below the 
maximum lift by suction. 

78. If the pump pounds soon after the beginning of a 
stroke, when running fast, it shows that the pump chamber 
is not filling and that the plunger is striking the incoming 
water on its return stroke. A suction air chamber will help 
to remedy the evil. Obstructions under the suction or 
delivery valves will cause a very decreased output or total 
failure. A suction strainer or end of suction pipe becoming 
embedded in sand or clogged with foreign matter will cut 
off the supply from a pump. 

79. Air pockets under the delivery valve deck, caused 
either by bad design or a shifting core, will very much 
reduce the capacity and efficiency of a pump. The effect of 
the air jxjcket is to entrap air, which is compressed to 
delivery-water pressure and expands again on the suction 
stroke. If the relative capacity of the j)ocket to the plunger 
displacement is sufficient, the entrapped air will expand to 
atmospheric pressure, reducing the suction lift to zero; this 
defect, however small, will always reduce the suction lift 
and is not easy to remedy; its existence should always be 
cause for the rejection of a pump. 

80. Pounding in pumps is sometimes caused by the 
water lagging behind the plunger, due to the friction of a 
small, long, horizontal suction pipe. When suction pipes 
have a long horizontal run, they should be one or two sizes 



81. Pumps sometimes fail when ihe full head is resting 
upon the delivery valves by the air between the suction and 
delivery valves being expanded and compressed by the ] 
motion of the plunger. Air cocks should be provided close up j 
under the delivery decks for discharging the air until the j 
plungers have taught the water. If only a simple cock is ] 
fitted, it must be opened during the delivery stroke only and | 
closed shortly before the suction stroke commences. This i 
is to be repeated until a steady stream of water issues from ] 
it during the delivery stroke. An automatic air valve, | 
which is simply a small spring loaded valve opening out- 
wardly and closing automatically during the suction stroke, | 
is preferable; this valve should be secured to its seat after a. A 
steady stream of water issues during the delivery stroke, ] 
Violent jarring and trembling of the pump arises from the 1 
delivery air chamber becoming filled with water. It should I 
be recharged with air by means of the air-charging pump, a ] 
near-by air compressor, or by a hand air pump. 


83. The steam end of pumps should not be taken apart 
needlessly, especially the steam end of direct-acting pumps 
with steam-thrown valves, as their action is quite compli- 
cated, and a very slight misadjustment will cause a failure. 
If at any lime it becomes necessary to dismantle the pump, J 
all the parts, if not already marked, should be plainly marked j 
with steel letters or numbers, rather than with a prick punch 1 
or chisel, and suitable gauges, by which all parts can be 1 
returned to their correct relative positions, should be made, I 
if this is deemed advisable. In many duplex pumps there! 
are very slight differences in the two sides; for instance, theJ 
crossheads that drive the valve levers are not keyed inJ 
exactly the same position on the piston rods and the rods! 
are not interchangeable; the pump will not run succesafuIlK 
if they are interchanged. In some pumps with steam-J 
thrown valves, the valve chests are bolted to the cylinders, 1 

35 PUMPS. 39 

and are reversible so far as fitting and bolting goes, but the 
auxiliary ports are not reversible and will be shut off in both 
valve chest and cylinder by reversing the chest. In placing 
the gasket between the valve chest and cylinder of pumps 
with steam-thrown valves, care should be taken to cut pas- 
sages through the gasket for the auxiliary ports. The valve 
levers, pins, and all connections between the piston rod of 
one side of a duplex pump and the valve of the opposite side 
should be kept in good condition, as the failure of these 
parts will cause a serious accident. 

83. On duplex pumps the amount of lost motion between 
the valve stem and the valve should be very carefully 
adjusted ; too little lost motion will cause short stroking, 
while too much will allow the pistons to strike the heads. 
If the pistons strike the cylinder heads, the dash relief valves, 
if fitted, should be closed until the stroke is shortened suffi- 
ciently for the pistons to clear the heads. If the stroke 
becomes too short, the opposite course should be followed. 
If no dash relief valves are fitted, the lost motion should be 
made smaller in case the pistons strike the heads. 

84. When a compound pump is fitted with a cross 
exhaust and it is seen that the pump is unable to complete 
its full stroke, the valve in the cross exhaust should be 


85. Testing the Suction Pipe. — Leaks are the most 
troublesome and most frequent sources of loss of efficiency 
in pumping machinery. Leaks in the suction pipe or suc- 
tion system affect the pump most and often cause its com- 
plete failure. These leaks can sometimes be detected by 
the ear, or the flame from a common tallow candle will often 
locate a leak in the suction by being drawn towards the hole 
by the air. Sometimes these leaks are very numerous, but 
so small that any one of them would be difficult to locate and 
be of small importance ; at the same time, their combined 
effect may be sufficient to seriously affect the working of the 

40 PUMPS. § 35 

pump. The best way to locate these leaks, which may be at 
the joints or along the body of the pipe, is to stop up the 
inlet end of the pipe, uncover it completely, and then put a 
water pressure on it, say from 40 to 50 pounds per square 
inch. Any leaks, however small, will then be readily 
detected. The suction pipe should always be tested for 
leaks before it is covered, if laid in a trench or otherwise 
made inaccessible, because it must be made tight before the 
pump will work successfully. 

86. Deliver^' Pipe I^eaks. — Leaks in the delivery pipe, 
while common and at times more difficult to remedy than 
leaks in the suction, are plainly evident. They do not affect 
the action of the pump or its efficiency to any extent, the 
loss being exactly proportional to the magnitude of the leak. 

87. Jlopairin^ Leaky Pipes. — Probably the most satis- 
factory method of procedure in case a leaky section of pipe 
is discovered is to discard it and replace it with a new one. 
Circumstances, however, do not always permit this to be 
done, and then temporary repairs should be made. The 
manner of making the repair obviously depends on the 
position and extent of the leak and calls for the exercise of 
judgment and some skill. 

88. Small leaks in the form of pinholes in the suction 
pipe can generally be stopped effectually by a thick coat of 
red-lead putty si)read over the pipe where the leaks occur. 
This should be covered with several layers of canvas covered 
on both sides with red-lead putty and wound as tightly as 
possible around the pipe. The canvas should then be 
secured by wrapping it with strong twine or annealed 
coj)per wire, put on as tightly as possible. If the suction pipe 
is split, it is usually well to cover the split part with a piece 
of sheet metal, preferably sheet lead, bent to the curvature 
of the pipe and put on with red-lead putty. The canvas 
should be wrapped over this. 

.\ permanent repair in case of pinholes can be made by 
drilling out the pinhole with a twist drill and tapping out 

the ho!c. A closely fitting thrciuieO plug of wift steel or 
wrouj;ht iron is then screwed in and the end riveted over. 

89, Small pinholes in delivery pipes can often be stopped 
up by the same means given in Art. 88 for suction pipes. 
If the leak is extensive, 
however, it will gener- 
ally be necessary to use , 
a pipe claiup. Such > 
clamps may be made in 
a good many different 
ways, according to the 
location and extent of 
the leak and the facilities for repair. One of the simplest 
pipe clamps is shown in Fig. 'i'd. It consists simply of a 
piece of sheet iron or sheet steel of sufficient width to 
cover the leak and bent to the form shown. A piece of sheet 
packing, which may be covered with red-lead putty to 
advantage, is placed over the leak and the pipe clamp is then 
placed over this and the ends drayn together by the bolt 

The clamp shown in Fig. 2:! is only adapted for small 
pipes. For large pipes the clamp must be made in two 

90, Testing Air Chambers. — Air chambers must be 
absolutely tight. They are usually tested by closing all 
openings and then pumping air into them until the working 
pressure is reached, as shown by a pressure gauge. After 
a-i hours this gauge should show no reduction of pressure. If 
the air chamber does not pass this test, the leaks may be dis- 
covered by filling it with water subjected to the working 
pressure. If there are a number of leaks, the chamber 
should be condemned; if only a few small leaks exist, they 
can usually be effectually stopped by drilling a hole at the 
leak and screwing in a plug. 

91, Tieakage of Pistons and Plunders. — The plungers 
of inside-packed or center-packed plunger pumps shotdd be 

48 PUMPS. g 35 

tight themselves, besides making a tight joint through the 
stuffingboxes, in order that water may not pass from one 
side to the other. The manner ni testing will depend on 
their design, the general method of procedure being the sub- 
jecting of one side of the plunger to an air pressure or 
hydrostatic pressure at least equal to the working pressure. 
If leaks are discovered, judgment has to be used as to the 
manner of repairing them or whether to condemn the 
plunger. In some designs of inside-packed and center- 
packed pumps with closed hollow plungers, the weight of the 
plunger is so proportioned to its displacement as to relieve 
the stufiingboxes of nearly or quite all of its weight ; it is then 
important that they be absolutely water-tight. 

93, Lcakugre Past Platous and Plungers.— With pis- 
ton pumps and inside-packed plunger pumps there is liable 
to be considerable unnoticed leakage. If it is extensive, it 
can be heard by placing the ear against the pump chamber. 
It is best with this style of pump to make regular inspec- 
tions for leakage past the plunger or piston, providing suit- 
able pipes and apparatus by means of which pressure can be 
put on one side of the packing or piston while the other side 
is exposed for ins[)ection. With outside-packed plungers 
there can be no unobserved leaks past the plungers, and this 
is the principal reason for their use. 

93. Leaks Past the Talves. — Leaks past the suction 
arid delivery valves can readily be tested when the piston or 
plunger is being tested for leaks past ihem. The delivery 
and suction valves should be tested separately ; tne fact that 
the column of water in the delivery pipe does not drain out 
while standing is not proof that both sets of valves are tight, 
since either set will support the water while the other set 
may be leaking badly, 

94. To test the suction valves for leakage, disconnect 
the suction pipe or take any other convenient steps that will 
allow the leakage to be seen. Fill the delivery pipe full of 
water, having removed enough delivery valves to allow the 
pressure to reach all the suction valves, and observe which 

§ 35 PUMPS. 43 

valves, if any, are leaking. When there is a valve in the 
.delivery pipe, this may be shut and water pumped into the 
pump cylinder with a small force pump, running the pressure 
up to the working pressure. Care must be taken, by remov- 
ing delivery valves if necessary, that the pressure reaches 
all the suction valves. 

96. The delivery valves can be tested by filling the 
delivery pipe or by closing the valve in the delivery pipe 
and pumping water into the delivery pipe between its valve 
and the pump delivery valve. The pump chamber must be 
open so that the leaks can be seen. 


96. By surging of the water flowing through pipes is 
meant that its velocity of flow not only is not constant, but 
that the direction of flow reverses for a short period. This 
condition often exists in pumping machinery having very 
long suction or delivery pipes. It may occur either in the 
suction pipes or in the delivery pipes, being, however, most 
severe in the latter. Crank-and-flywheel pumps, owing to 
the variation in the piston speed between the beginning and 
end of the stroke, are particularly liable to cause surging, 
which is due entirely to an irregular delivery. 

97. Duplex direct-acting pumps, owing to the uniformity 
of delivery and the absence of heavy weights, such as fly- 
wheels, are little liable to cause surging, and when liquids 
must be moved through long mains, an instance of which 
are the long oil pipe lines, this pump is chosen. Crank-and- 
flywheel pumps forcing water through very high delivery 
pipes, as occurs in mine work, are seriously affected by the 
surging of the water. Air chambers do not help matters, 
but probably aggravate them by forming an elastic cushion 
for the column of water to rebound from. The effect of 
surging water is to vary the pressure on the pump and 
mains, sometimes from zero to twice the pressure due to 
the vertical height, resulting in broken pump chambers. 

44 PUMPS. § 35 

pipes, and not infrequently in damage to the working parts 
of the pump, for the actual resistance to these shocks is not 
met until they arrive at the flywheel rim. 

98. The remedying of surging is not easy of attainment. 
Air chambers placed along the delivery pipe at intervals are 
employed occasionally, the aim being to break up the vibra- 
tions of the surging water and get them out of step or out of 
harmony with the motion of the pump. Alleviators are 
sometimes used in place of air chambers to relieve the shock, 
and not being so elastic do not encourage surging to the 
extent that air chambers do. When for economical reasons 
it is desired to use the crank-and-flywheel pump, the varia- 
tions in pressure and the liability to surging can be very 
much reduced by using the three-throw crank with the pins 
set at 120° from one another. 

99. Surging in long suction pipes is liable to occur 
especially when the water flows to the pump by gravity; 
this is not so difficult to overcome or so serious in its effects 
as surging in the delivery pipe, for the reason that the 
direction of the force resulting from the surge is through 
the pump valves and into the delivery, or in the natural 
direction of the water, while the shock due to surging in 
the delivery pipe comes against the valves and must be 
withstood by the machinery. 

100. To prevent shocks due to surging reaching the 
machinerv, a liberal sized air chamber is needed on the 
suction main near the pump, and in addition spring-loaded 
relief valves may also be fitted to the main. These relief 
valves simply limit the pressure due to an unusually heavy 
surge that cannot be taken care of by the air chanjber. 


lOl. In mine and artesian-well work, large quantities of 
air arc* often mixed with the water, due t(^ local disturbances 
in liie souree of supply, sueh as water discharging into it in 
the furni of spray. When such a mixture of air and water 





is pumped, the pump will have a jerky motion, that is. 
instead of moving steadily it will miive in jumps, and in the 
case of direct-acting pumps there is danger of striking the 
cylinder heads. Besides, on account of the uneven dis- 
charge there will be violent disturbances in the delivery 
pipe, The only effectual remedy is to remove the air before 
it arrives at the pump. 

102, Fig. 2-1 shows the installation of a pump taking 
its water from an artesian well a, the water being highly 
charged with air and gas. A large suction air chamber d Is 
put into the suction pipet; the water passes through the 
strainer tf to the pump e. A vacuum pump / is connected 
by the pipe^ to the top of the air chamber and not only 
maintains a vacuum in the chamber, but draws the air and 
gas out of the water in the chamber and before it reaches 
the pump. The gauge glass A not only shows the height of 
water in the air chamber, but also allows the bubbles of 
air and gas rising through the water to be seen. The 
vacuum pump is simply an ordinary steam pump pumping 
air instead of water; it is running constantly and its speed 
is regulated to suit the height of the water in the air 
chamber. ■ 


103. The steam valves of duplex pumps have no outside 
or inside lap, consequently when in their central position 
they just cover the steam ports leading to opposite ends of 
the cylinders. With all these valves a certain amount of 
lost motion is provided between the jam nuts and the valve. 
This lost motion in small pumps is within the steam chest, 
while in large pumps it is outside and may be adjusted while 
the pump is in motion. The first move in the process of 
setting the valves of duplex pumps is to remove the steam- 
chest bonnets and to place the pistons in their mid-stroke 
position. To do this, open the drip cocks and move each 
piston by prying on the crosshead, but never on the valve 
lever, until it comes into contact with the cylinder head. 

§ 35 PUMPvS. 47 

Make a mark on the piston rod at the steam-end stuffingbox 
gland. Move each piston back until it strikes the opposite 
head, and then make a second mark on the piston rod. 
Half way between the first and second mark make a third 
one. Then, if each piston is again moved until the last 
mark coincides with the face of the gland, the pistons will 
be exactly at their mid-stroke position. After placing the 
pistons in their mid-position, set the valves central over the 
ports. Adjust the locknuts so as to allow about ^\ inch lost 
motion on each side. The best way of testing the equal 
division of the lost motion is to move each valve each 
way until it strikes the nut or nuts and see if the port 
openings are equal. When the port opening has been 
equalized, the valves are set. The valve motion need not 
be and should not be disturbed while setting the valves. 
Too much lost motion will tend to lengthen the stroke and 
may cause the piston to strike the cylinder heads, while on 
the other hand when there is not enough lost motion, the 
stroke will be perceptibly shortened. The proper amount of 
lost motion to give a certain length of stroke can only be 
found by trial for each particular pump. 

104, If only one valve of a duplex pump is to be set, 
bear in mind that it is operated by the piston of the opposite 
pump. Place that piston in its mid-position and then set 
the valve as previously explained. 

//. S. K-v 


(PART 3.) 



1. The displacement of a pump for a single stroke is 
the volume of water that would be displaced (that is, driven 
out of the cylinder) by the piston or plunger during that 

In calculating the displacement of a pump in a given time, 
care must be taken to consider the number of strokes during 
which water is discharged. Thus, for a single-acting pump, 
water is discharged only when the piston moves in one 
direction ; and with the double-acting pump the number of 
strokes during which discharge occurs is equal to the total 
number of strokes that the piston makes. With a duplex 
double-acting pump, it is customary when giving the number 
of strokes per minute to refer only to the number of strokes 
made by one piston, which, obviously, is only one-half the 
total number of strokes made. As practice varies, how- 
ever, among engineers in this respect, it is best to find out 
in each case, by inquiry, whether the number of strokes of 
one piston or of both pistons in a given time is meant when 
the number of strokes is given. In the case of a crank- 
driven pump, for a single single-acting pump the strokes 
will be equal to the revolutions of the crank; for a single 

For notice of copyrivcht, see paj^e immediately following the title page. 

2 PUMPS. § 36 

double-acting and a double single-acting crank-driven pump 
the strokes will equal twice the number of revolutions; 
for a triplex single-acting crank-driven pump the strokes 
will equal three times the number of revolutions; and 
for a triplex double-acting pump, six times the number of 

2. The displacement of a pump in a minute in cubic 
feet, gallons, or pounds is given by the following rule : 

Rule 1. — Multiply the length of stroke in inches by the 
mean effective area of the pump piston or plunger in square 
inches and the number of strokes per minute. The product 
is the displacement in cubic inches. To reduce the displace- 
ment to pounds^ multiply by the weight of a cubic huh of the 
liquid pumped ; to reduce to cubic feet ^ divide the displacement 
by 1,728 ; to reduce to Winchester gallons, divide the displace- 
ment by 231 ; to reduce to English imperial gallons, divide 
the displacement by 277,27, 

Or, D^=LANS, 

^ _ LAN 
'"■ 1,728' 
^ _ LAN 


D^ = 

"^ 277.27' 

L — lenp^th of stroke in inches; 
A — area of piston or phmger in square inches; 
X —- niiiiii)cr i)f delivery strokes per minute; 
\ — wcii^ht in pounds of a cubic inch of the liquid, 
J)^^ .- (lisplarenient in pounds per minute; 
/). _- (lis|)laccnient in cubic feet per minute; 
I\u, — displacement in Winchester gallons per minute; 
P,.., = displacement in English imperial gallons per minute. 

•i. Attention is here called to the fact that there are 
three dilTrrent gallons in use, of which the Winchester, or 
wine, gallon, measuring 'I'.W cubic inches, is most commonly 

§ 36 PUMPS. 3 

used in America. In Great Britain and her colonies the 
imperial gallon, holding 277.27 cubic inches, is largely used 
as a measure. In most English-speaking countries the beer 
or ale gallon of 282 cubic inches capacity is also used, but 
almost exclusively for measuring the liquids mentioned. 
When the discharge of a pump is given in gallons in the 
United States of America, it is always understood, unless 
distinctly stated otherwise, to be in gallons measuring 
231 cubic inches. 

4. The mean effective area of the piston or plunger 
is equal to the area corresponding to the diameter only in 
case of outside-packed plunger pumps. In case of inside- 
packed and center-packed plunger pumps and double-acting 
piston pumps, the mean effective area is found by dividing 
the sum of the piston or plunger area and the same area 
diminished by the area of the piston rod by 2. Thus, in a 
double-acting inside-packed plunger pump having a plunger 
10 inches in diameter and a 2-inch piston rod, the mean 

a .. . 10' X .7854 + (10* X .7854 - 2" X .7854) 

effective area is ;^ — 


= 76.97 square inches. In case of a single-acting piston 
pump, which generally is a lift pump, the effective area will 
be the area of the piston diminished by the area of the 
piston rod, since the piston rod is on the delivery side. In 
case of a differential pump having the plunger areas in the 
ratio of 1 to 2, the area of the smaller plunger is the effec- 
tive area. In rough, approximate calculations of displace- 
ment, the correction for the area of the piston rod or plunger 
rod need not be made, and then the area of the piston or 
plunger is considered as the effective area. When the dis- 
placement requires to be accurately known, however, the 
mean effective area should be used. 

Example 1. — A single-acting plunger pump is driven by a crank 
whose radius is 8 inches and whose number of revolutions is 30 per 
minute. If the plunger is 6 inches in diameter, what is the displace- 
ment in cubic feet per minute ? 

Solution. — The number of discharging strokes of the plunger is 
equal to the number of revolutions of the crank, or 30 per minute ; the 

4 PUMPS. § 36 

length of the stroke is 8 X 2 = 16 inches. The area of the plunger 
is 6* X .7854 = 28.27 square inches. Applying rule 1, we have 

^ 16 X 2 8.27 X 30 r- a. f^ a 

De = ^7 ^c%6 = '^'^ cu. ft. per min. Ans. 

1, i>io 

Example 2. — A center-packed double-acting duplex pump has 
plungers 24 inches diameter with 4-inch plunger rods. Each plunger 
makes 80 strokes per minute, the length of stroke being 32 inches. 
What is the displacement in American (Winchester) gallons per minute ? 

Solution — The mean effective area of the plungers is 
24* X .7854 + (24* X .7854 - 4* x .7854) 


= 446.1 square inches. 

Since the pump is duplex, there are 30 X 2 = 60 strokes per minute. 
Applying rule 1 , we get 

Dag = ' — — nQ{— — = 3,707.8 gal. per min. Ans. 


6. The theoretical disoliarge of a pump is equal to the 

6, The actual discharge is generally less than the dis- 
placement, owing to leakage past the valves and piston and 
also to the return of water through the valves while they are 
in the act of closing. 


7 The difference between the displacement and the 
actual discharge, expressed as a percentage of the displace- 
ment, is called the slip of a pump. 

8. Xegatlve Slip. — When the column of water in the 
suction and discharj^c pipes of a pump is long and the lift 
moderate, the encrj^y imparted by the piston during the 
discharge stroke may be sufficient to keep the column 
in motion durinti^ all or a part of the return stroke. Under 
thrsc conditions, the actual discharge may be greater than 
the displacement, and the slip is then said to be negative. 

§36 PUMPS. 5 

Rule 2. — To calculate the slip of a pump, find the differ- 
ence between the displacement and the actual discharge, mul- 
tiply it by 100^ and divide the product by the displacement. 
The quotient will be the slip expressed in per cent, of the dis- 

Example. — A single-acting plunger pump with a plunger 8 inches in 
diameter and 36 inches stroke discharges 33.5 cubic feet of water per 
minute when making 35 discharging strokes. What is the slip ? 

Solution. — By rule 1, the displacement is 
36 X 8* X .T854 X 35 


By rule 2, the slip is 

(36.652 -- 3&5) X 100 

= 36.652 cubic feet per minute. 

8.6^ per cent., nearly. Ans. 


9. The useful Mrork in foot-pounds done by a pump is 
the product of the water raised in pounds multiplied by the 
vertical distance in feet from the surface of the water in 
the well or supply reservoir to the outflow end of the dis- 
charge pipe. 

10, The actual work is always greater than the useful 
work. Force is required to overcome the friction of the 
piston or plunger in the cylinder or stuffingbox, and con- 
siderable force is also required to overcome the friction of 
the water in its passage through the pipes and the valves 
and passages of the pump. Some force must also be 
expended in giving the water the velocity it has when it 
lea*^es the discharge pipe. 

The theoretical force required to drive the piston is equal 
to its area multiplied by the pressure due to a head equal to 
the vertical distance from the surface of the water in the 
well to the outlet of the discharge pipe. The actual force 
can be found by the aid of a pressure gauge or indicator 
attached to the pump cylinder, which will give the actual 
pressure on the piston in pounds per square inch. 

6 PUMPS. § 36 

According to the principles of hydraulics and the flow of 
water through pipes, it is evident that the power required 
to overcome the frictional resistance of the water will be 
reduced by making the pipes large and direct and the pas- 
sages through ttie valves and pump of ample size and as 
direct as possible, so as to avoid loss from sudden change of 
direction of flow. 


11. The indicated horsepower developed in the cylinder 
or cylinders of a steam-driven or compressed-air-driven 
pump is found in exactly the same manner as with a steam 
engine and from the same data. The horsepower usefully 
expended is given by dividing the useful work done by the 
pump in 1 minute by 33,000. The ratio of the usefully 
expended horsepower to the indicated horsepower is an 
indication of the mechanical efficiency of the pumping 
apparatus considered as a whole. 

ItJ, It is often required to estimate what horsepower will 
be required to pump a given quantity of water per minute 
to a given elevation or against a given pressure. This 
problem can only be solved approximately by a general 
rule, there being a number of variable factors entering into 
the solution, such as iht* general run and length of the 
j)iping, the desij^ii of the water end, the degree of workman- 
shij). etc. The iniluencx' of some of these factors cannot be 
(lc-irrniini(l beforehand with any great degree of accuracy, 
an<l lor that reason any general rule for estimating the 
rrqui red hoiscpower nnist be i)ased on a low mechanical 
rtVit icncy Ml' the piinipinj^- aj){)aratus in order to leave an 
ani|»le niai";^in lor sat'ety. 

1 .*{. In e^timatinii- upon the probable horsepow^er, it is 
occasional!}' necessary to convert a given pressure into a 
head ot water in feet that will exert the same pressure. 
This can be readily done by multiplying the given pressure 
bv 'l.:\. 

g 36 PUMPvS. 7 

14, If the volume of water to be discharged per minute ^ 
is given in cubic feet and the vertical height from the suc- 
tion level to the discharge level in feet is known, the foot- 
pounds of work to be done is G2.5 X volume X vertical 
height, taking the weight of a cubic foot of water as 
62.5 pounds. Consequently, the theoretical horsepower is 

62.5 X volume x vertical height 

33,000 ' 

foot-pounds of work to be done 


Assuming an efficiency of 70 per cent., the actual horse- 
power will be 

100 X foot-pounds of work to be done 

70 X 33,000 

_ foot-pounds of work to be done 
"" 23,100 

Hence the following rule : 

Rule 3. — To estimate the probable horsepoiver required to 
drive a pump^ multiply the weight to be discharged per min- 
ute by the vertical lift and divide by 23^ 100. 

Or, //. = -i'^ 


where H^ = estimated horsepower; 

]V= weight of water discharged per minute in 

L = vertical lift in feet. 

Example. — About what horsepower will be required to discharge 
85() gallons of water per minute, the total lift being 1^20 feet ? 

Solution. — The weight of the Winchester, or ordinary American, 
gallon is H.34 pounds, nearly. Hence, the weight of water to \ye 
pumped per minute is 350 X 8.34 = 2,919 pounds. 

Applying rule 3, we get 

//f = ■-— — = 40 H. P., about. Ans. 

16. When the weight of water to be discharged per min- 
ute and the pressure against which it is to be pumped are 

r _ _'t s 


*' V-, -. T : . - -• 1' > - r Pi : tr f. ceis weight X pres- 
--rt 1 ■' .----.:: ::^ i.^ t::^.::r:::ii:T :c ?•> per cent., the 

-i ? 

*i:j:ni X pressure 

Rale 4. — ." - v;- ; . -^^ '*'i\j k^^rs^-fczj^r^ rnultiplvthe 
: .::'':: *" :. : - ' •. ' i :.-•. r -•. "" ■»r:Ti.v rr //r«- pressure 

- - -Lf" 
"'• -•■ - : . .4.;- 

x'-rre -^ = i'T<5u-e r^r •>:-.Lire inch: 

;i" r^ ■*-r-.^'r_': : Tj.irr rrr minute. 

Ir. rules 5. «. 7. i" i S thr 'rt:er> have the same meaning 

Ex\.M?iz— A T-rr- :■? t r-— r -t**' .-"r:-: fe«t of waiter per hour 
' r..'-* . '" '-z : *^' :• -~1- r<rr s^i^rc :zch- Estimate the prob- 

^1 t.K 

" ■ .r^f"* "• T 

^ ^ _K-:-.:r.< \'r.- ■■ .mttt :*rr '. -r :o pounds per minute. 


'':;-4. -r-- 

111 14. » 

11;^ ,.,,,,. :,. . .;;:;:;. :::• :.-.-:c.?: lift zcitJi a i^h'cn 

■ - : >.. " :..■': :ij^»*» and divide by 

1 • • .1 • 

, , . .V ,i 111.': ..:-'■>» wcr engine is to discharge 

• > 11' \v t.i;:!. rr.av ihi> water be lifted, 

•,- ;■ :'.': .>• ''■'■■'■ '-l''^ 
-•• ' 11.) .) It. Ans. 

§ 36 PUMPS. 9 

17. Hiile 6. — To estimate the probable (iise/iarj^e in 
pounds per minute^ divide 23^ 100 times the horsepower by the 
vertieal lift in feet, 


Or, IF=: 


Example. — How many pounds of water per minute, approximately, 
can a pump driven by a 25-horsepower engine discharge at a height of 
42 feet ? 

Solution. — Applying rule 6, we get 

W = ^^'^^ X ^^ = 13,750 lb., about. Ans. 

18. Rule 7. — To estimate the pressure that ean be pumped 
against, multiply the horsepower by 10,0^3 and divide by the 
weight to be pumped per minute. 

Or P- IQiMi^* 

' ~" " \V 

Example. — A 9-horsepower pump is to discharge 6,000 pounds of 
water per minute. Estimate against what pressure this can be 

Solution. — Applying rule 7, we get 

P = — ' ^^ — = 15 lb. j>er sq. in. Ans. 

19. Rule 8. — To estimate the probable discharge in 
pounds per minute^ multiply the horsepower by lO.OJf-J and 
divide by the pressure to be pumped against. 

10,043 //, 

Or. ]V = 


Example, — How much water may a pump be estimated to discharge 
in Winchester gallons per minute when the pump is 4()-horsepower 
and pumps against a pressure of 100 pounds per square inch ? 

Solution. — Applying rule 8, we get 

,„ 10.04:3x40 .^.^^ , 

ly = — = 4,017.3 pounds per minute. 

Since a Winchester gallon weighs 8.34 pounds, we have 

4,Ul I. ^ 401 - I \ 

— 4S1. 1 gal. per min. Ans. 

10 PUMPS. § 36 


20, Before the size of a piston or plunger for the water 
end of a pump can be determined, the quantity of water to 
be pumped and the piston speed must be known. The piston 
speed is the number of feet traveled per minute by the 
plunger when discharging water ; that is, it equals the length 
of the stroke in feet multiplied by the number of working 
strokes per minute. Tf the pump is double-acting, the 
number of working strokes is the same as the total number 
of plunger strokes, both forward and back ; if single-acting, 
half that number. If the pump is duplex, it is advisable to 
consider only one side in determining the size of plunger or 
piston, designing it to suit one-half the total quantity of 
water to be delivered. In direct-acting steam pumps the 
piston speed is generally about 100 feet ; at least it is custom- 
ary to design them on this assumption, and then to run the 
pump faster or slower to suit the required delivery, opening 
or closing the throttle valve to vary the speed of the pump. 

21. Knowing the actual volume of water to be discharged 
in 1 minute in cubic feet, the plunger or piston area in 

square feet will be — r ^ — ,, theoretically. But in prac- 

^ piston speed '' ^ 

tice the diameter of the plunger or piston is given in 

inches, hence the area should be expressed in square inches. 

^- discharge in cubic feet X 144 

Then, area = . , . . , 

piston speed in feet 

and the corresponding diameter in inches will be 

/ discharge x 144 
y .7854 X piston speed' 

23. Since there is always more or less slip of the water, 
it is usual to design the pump on the assumption that it 
must pump 1.25 times the actual amount of water. On this 
assumption the plunger or piston diameter in inches will be 

discharge x 1.25 X 144 
.7854 X piston speed ' 

§ 36 PUMPS. 1 1 

X discharge 


piston speed 

Rule 9. — To find the diavtetcr of a plunger or piston in 
inches, multiply the discharge in cubic feet per minute by 229 
and divide the product by the piston speed in feet per minute. 
Extract the square root of the quotient. 


where rf= diameter of piston or plunger in inches; 
D = actual discharge in cubic feet per minute ; 
S = piston speed. 

When the discharge is given in pounds, gallons, or any 
other unit of volume, it should be reduced to cubic feet 
before applying rule 9. 

Example. — What should be the diameter of a pump plunger required 
to discharge 130 Winchester gallons per minute, the speed of the 
plunger being 90 feet per minute ? 

Solution. — Reducing the gallons to cubic feet, we have 

— — = 17.378 cubic feet per minute. 
Applying rule 9, we get 

, ./229X 17.378 ^ „^ . , , 

a = 4/ Q^r = 6.65 m., nearly. Ans. 

23. Rule lO. — To estimate the probable discharge in cubic 
feet, square the diameter of the plunger or piston in inches 
and multiply by the piston speed. Divide the product by 220. 

d^ S 

Example. — How many pounds of water per hour may a duplex 
double-acting pump be expected to discharge when the diameter of 
the plungers is 6 inches, the length of stroke 24 inches, and each 
plunger makes 40 strokes per minute ? 

Solution. — The piston speed is \\ x 40 = 80 feet per minute. The 
probable discharge per minute in cubic feet, by rule lO, is 


D = 

229 ' 

6« X 80 X 60 

per hour, D = ^^^ 

1-2 PUMPS. §36 

The discharge in p "unds per hour, taking S2.5 poands as the weight 

^ _ ^ ^> X m X eg. 5 

for one >ide «•: the pump. F»»r bi-th sides, 

/>= — ^^ = »l.a23 lb. Ans. 

In applying rule lO it is to be observed that rhe result 
will be less than ijivcn i»y multiplying the displacement per 
stroke by the numl>er «>t strokes per minute, as called for by 
rule 1. The reas«.>n for this discrepancy is obvious; rule 1 
jrives the theoretical discharge, while rule lO gives about 
what the pump may actually be expected to discharge. 

*i'i» In direct -acting steam pum|>s the normal piston 
speed is generally 1<m> feet per minute. On this basis the 

probable dischar^re in cubic feet, bv rule lO, is Z^ = — , 


, . „,. , '. u 1 u • ^/'X 100 X 1,728 

and in \\ mchester vraii« »ns the discharjre is r-^:: r— 7^ — 

^ 231 X 229 

Kule 11. — 7r roughly iif/^riwirmi/t' the probable normal 
discliar^i r/ii «/'.■' <t.'-£/i:';/;^' swii/: f^nr/i/* in iralloMS, multiply 
tJw saitarc cr fJu- dia:iu':t.r . t !»u plitu^cr or piston by 3.26. 

where P . — disohariie in i^all^ns per minute; 

(/ — <::anK-ier "t pisifii v>r plunger in inches. 

*i.">. riir ir.r rrtival n •iiiKil disoh.arge in gallons per 
niiiv.;:c a: .. :>:>:. n >i)retl .•! 1«»<) u-ct is triven almost exactly 
by niult::<!yi:v4- ip.u >qiiari' «'f iIk- tliamcier of the plunger or 
I>i>i«>n hy I. I•^'^ a iluj.>lex pump the discharge is double 
that i^ivcn l>y ruif II. 

KxAMiM.K— W'b.a: ir.av the discharire in gallons of a duplex pump 
with f>-in. h |.l:]':-rr> t.c r.'iijrhly olin^.alod at • 

SoLLTi.x - Ai'j.Iviiv^^ ni!e 1 1, wt- .i:t.-i P - :• *J» \ fv for each side, 

L>j _ :i.'2*j >; (i- ;.' '^^ 1^ '2'o'y ^al. jht min. Ans. 

§36 PUMPS. 13 

2Q. Having determined the proper plunger or piston 
diameter for the chosen piston speed, it remains to choose 
either a length of stroke or a number of strokes in order to 
determine either the number of strokes or the length of 
stroke. The ratio of the diameter to the length of stroke 
varies between very wide limits in practice, being as low 
as 1 : 1 and as high as 1 : 5. Obviously, the greater the 
ratio, the fewer times will the valves have to be moved, 
hence a great ratio is generally chosen for pumps that have 
to run continuously in a hard, rough service. Having 
chosen a length of stroke, use the following rule: 

Rule 12. — To find the nuinhcr of strokes^ divide the piston 
speed in feet by the chosen ienj^th of stroke in feet. To find 
the length of stroke in feet, divide the piston speed in feet by 
the number of delivery strokes per tninute, 

Or, N = L, 

and Z = ^, 

where P= piston speed ; 

N =. number of delivery strokes per minute; 
L = length of stroke in feet. 

Example. — What should be the length of stroke for a piston speed 
of 100 feet if the number of strokes per minute is 40 ? 

Solution. — Applying rule iSi, we get 

/ _ 1 O — O ^i f t 

or 2.5 X 12 = 'M) in. Ans. 


27. In a direct-acting steam pump the size of the steam- 
end cylinder depends on two factors, which are the steam 
pressure available and the resistance against which the 
pump is to force the water. The stroke of the steam piston 
and water piston obviously are the same, both being rigidly 
connected to the same rod. 




tJ8. Thtr : rc^es ic::r.i: n the steam piston and water 
;\>: r. a^t^ equ^l when :hr area of the steam piston X the 
stean: pressure = ire j. : water piston \ pressure pumped 
aj:air.>:. Bu: ir. rcer :ha: there may be an ample margin 
: • •-•vtr,^:r::r the rnjt: r-kl resistances, which make the 
actual re^isiar-v-e :.• :hr n ::• n -f the water piston greater 
ar..: !r->cser. :he : r.-^ that :r:::Tl< the steam piston forwards, 
the area :: :ht >:ear:: : :>: r. sh uli r^. at least. 40 per cent. 
:r. e\.^e>> : :> th- rr:::al area. On this basis, we have 
area .: >:ta:-: ::>t;r. 

'. 4 • a'ra : •»i.:rrr:>: n • pressure 

"t > -1 . - ^ 

'- ^ 

atT' : :>t n • pressure 
<:rarr. rre-ssure 

: ■*■-».::■ 

• r ressure 

Kulo I ^. 

.-.— Vt. ,. 

*■ :".:jr:?y: J:::\.:\'r: the 
- -. .* i, -vaj*'^ ''-v* cf the 

ton :• r i -.. - 

"■'i^-r ,*c tie steam 
■ ■ : r«; water :o be 

§36 PUMPS. 15 

Solution. — The area of the plunger is 8* X .'«'854 = 50.27 square 
inches. Applying now rule 13, we get 

. /1.8X 50.27X200 ,^ ^ . , 
dm = y =R = 15.5 in. Ans. 

29, It is to be observed that rule 13 applies equally well 
to steam- and air-driven pumps. It can also be applied to 
simple pumps of the crank-and-flywheel type using steam 
expansively. In the latter case, the mean effective pressure 
throughout the stroke must be taken as the available steam 
pressure. Rule 13 is especially useful in deciding whether 
a given pump will pump against a known pressure with the 
existing sizes of steam and water pistons. It will also be 
found very useful in selecting a pump for a given service 
from the catalogues of manufacturers. 

30, In boiler-feed pumps the steam pressure available 
and the pressure pumped against are practically equal, so 
that it might be expected that the area of the steam piston 
would be made about 40 per cent, larger than the area of 
the water piston. In actual practice it is foimd, however, 
that pump manufacturers prefer to make the steam piston 
about 3 times the area of the water piston in very small 
pumps and about twice the area of the water piston in 
large pumps. The steam piston of boiler-feed pumps is 
made so largely in excess of what it really needs to be 
merely as a matter of safety ; its large size simply tends to 
insure a prompt starting of the pump under almost all con- 
ditions likely to arise in practice. 

31, The steam end of direct-acting pumps and of direct- 
connected crank-and-flywheel pumps, where the steam and 
water pistons move together, is rarely proportioned on the 
basis of horsepower required to do the work, it being much 
easier to calculate the size of the steam end by rule 13. 

3t5. When a power pump is driven by a separate steam 
engine, through the intervention of belting or gearing, the 
engine itself is generally selected on the basis of horsepower 

//. S. v.— 10 

«pae far aaf Mfca 



Tie ocw brXOTce* the «>«^ daoe br ^ p«Bp aad s 
fjHM UMMflt of ccsl, Ncaa. «r he^t, mmms ascd to do tbe 
rfcic^Jkd theMmtfoi tWfMBBfL 
_-l> wnn K acma>aUiDe.9»f aabe«r<«a dsiT.ikc pomp will 
UM! a ifiattutf d waier tbroa^ x cenaio bagfat and tfaas 
pniurm a dcfaitc anmnit ol vorfe. To lio this work, tlie 
pamp ba> received from Ibe botlen a cntain namber iif heat 
anils or a oiuntirr iif poandsof sicun; or, if ibe tmtleisare 
irwrlude'l a* a pan of ibe trMctD, the work has been accom- 
pliabcH by con^'UminB a certain amount of coaL The pump 
ia credited «ilh the work it ha& performed in the stated time 
and ii chartii^ with the Dumber of heat units, pounds of 
• I'-iiin. 'T (li.timU 'if c'tal it has used induing the work. It is 
(•bill itial ttii '--■■D'jiny of the pump <ir pumping engine is 
iKT'.iiiiO'd ity the ratio (if the work t:>erf»rmed to the steam 
■'.(. Ml' I ',r 1:,- ".;il burned. Thus, if one pump does 

.' •••'<••'• i'f,\-i,.,\\n'\s iif work with a coal consumption of 

I'i'f |.'.ii(i'I .iij'I ;iii'.lher undt-r the same conditions does 
,;i, i,r,r, Mipo |-,^,i |,',iii)'ls andfoiisiimes only 60 pounds of coal, 
M,: l.iiLi I '^ ii|i-jiily thf moreeconomical, since the ratioof 

■ il .MtiMiJii|.ti..ii is Iarj;er. being (:t(i.OOO,000 -h 60) 

l'"> '11. 1" '»' f'">l-p'imit]s of work with a coal con- 

8 36 PUMPS. 17 


34, When the duty is based on the consumption of coal, 
it is customary to assume 100 pounds of coal as the fuel unit ; 
that is, the duty is defined as the number of foot-pounds of 
work performed for each 100 pounds of coal burned. Then, 

^ ^ - J /. , pounds of coal 
Duty = foot-pounds of work -r- — — , 

^ foot-pounds of work x 100 

or. Duty = 3 -z -. . 

•^ pounds of coal 

Rule 14. — To find the duty of a pump per 100 pounds of 
coal, multiply together 100, the iv eight of water pumped in a 
given time in pounds, and the vertieal distance in feet from 
the level of supply to the level of discharge. Divide the prod- 
uct by the coal consufnpt ion in the same time in poimds, 


Or, D^ 


where D = duty ; 

w = weight of water in pounds ; 
W = weight of coal in pounds ; 
// = vertical lift in feet. 

Example. — A pump raises 130,000 pounds of water 60 feet and the 
operation requires the combustion of 25 pounds of coal. What is the 
duty ? 

Solution. — Applying rule 14, we have 
D = ^^ ^ ^30 000 X 60 ^ 31 200.000 ft. -lb. per 100 lb. of coal. Ans. 

35. The duty based on the coal consumption is of practi- 
cal value, as it gives an idea of the coal required by a pump 
of a given type for the performance of a stated quantity of 
work. It is clear, however, that if a comparison of the merits 
of two pumps is to be made, the coal must be of the same 
quality in each case. Further, the boilers supplying steam 
to the pumps should be of the same type or at least have 
the same evaporative capacity. This is a point of great 
importance. One hundred poinids of good bituminous or 
anthracite coal may, under favorable conditions, evaporate 

18 PUMPS. § 3»5 

l.r»00 to l.lfK) pr>unds^»f water: that is, furnish that number 
of pounds of steam to the pump. In many cases, however, 
the KK) pounds of coal, if of inferior quality and burned 
under a p«^x>r b^^iler. will not furnish the pump more than 
4.V> to »?^i pounds of steam. Under such conditions the 
duty of the pump based on the coal consumption would not 
be a fair indication of its efficiency and would not serve as 
a satisfactory- basis for comparing it with other pumps. 


36. In order to avoid the drawbacks incidental to basing 
the duty <»f pump on the coal consumption, it is the custom 
of Si^;me pump makers to specify that the coal consumption 
shall be estimated on the supposition that a pound of coal 
evajK^rates 10 jx^unds of water. <»r. in other words, furnishes 
IM }><*unds rti steam to the pump. To make this clear, suppose 
that in a duty trial 3*2.<.M»n p^^unds **i steam were used by the 
pump: the duty of the pump w^iuld be calculated on the 
assumption that the coal consumptiMU was 32,000 -f- 10 
= -irt***) |x>unds. though 5 J mm* p<:>unds might actually have 
been used. If 1 pnjund of coal is assumed to furnish 10 pounds 
of steam, loo p<»unds of coal will furnish 1,000 pounds of 
steam : hence, the duty based on steam consumption may be 
(Uitin*:d as the number of f^M»t-|x«unds of work done by the 
pump per 1.«»'m» p.,unds <«f dry steam supplied it. Then, 

f«.»ot-pounds ..f w..rk y 1.<XM) 
* ' rxjuiids ••t Steam 

Rule 15. — 7 r ;-/ //.j r////: r/' J r '''/ ft'r IjXXt fOUHiis of 

(i^;. V . 'V^.j * O''- ' '^ ' - ^ ' V' •' '/ zciitcr pumped in 

/' '(•■•'I- . '■'.: ' '. '-::: i.' 'i:s:.n::i- :>• r\ : .' '"» ;/; tlw leirl of supply 
t' th... .',::.' '' •i:^:^:ar^c, a'ld Ij'^j". Divide by the weight of 

s!tani .:(^r/v:i I'l r"in[-is. 

wL'T'- ^ - \v« ;^':: of 'irv -tram -:ii':'".:r i in pounds and the 
olh'jr Iviv.-r- i.a'.'j liic >anic nicaniiv- as in rule 14. 

§3f) PUMPvS. 19 

Example.— A pump lifted 7,920,0(H) pounds of water 126 feet with 
8.100 pounds of steam. What is its duty ? 

Solution. — Applying rule 16, we get 

_ 1,000 X 7.920.000 X 126 

= 123,200.000 ft.-lb. of work per 1,000 lb. of dry steam. Ans. 

37. The basis of 1,000 pounds of dry steam is more 
scientific and better adapted for duty trials than that of 
lOO pounds of coal, but it is open, nevertheless, to objections. 
Not only is it difficult to determine the exact weight of dry 
steam entering the pump, but also 1,000 pounds of steam at 
lOO pounds pressure will do more work in the cylinder than 
1,000 pounds of steam at GO pounds pressure. If scientific 
accuracy is sought, the pressure of the steam should be 
specified in addition to the weight. 


38. On account of the objections to the basis of com- 
parison then used, a committee of The American Society of 
Mechanical Engineers in 1891 recommended a new basis for 
the estimation of duty. Whether the furnace consumes 100 or 
200 pounds of coal, whether the steam is at 00 or 100 pounds 
pressure, wet or dry, the steam cylinders of the pump or 
pumping engine receive in a given time a definite number 
of British thermal units. We have seen that if each of two 
pumps is allowed 100 pounds of coal to do a certain amount 
of work, one of the pumps may be at a disadvantage on 
account of the poor quality of the coal or the inefficiency of 
the boiler. If each is allowed 1,000 pounds of dry steam, 
there may be an inequality because of a difference in the 
steam pressure in the two cases. If, however, each pump is 
furnished with an eciual number of heat iniits, each has 
exactly the same stock in trade, and the merit of each pump 
can be gauged by the use it makes of the heat units furnished 
it, that is, by the ratio of the work performed to number of 
heat units supplied. 


39. If a pound <if w:iter has a ttiiijicrature of 'Hi", it 
requires Utili.l B. T. U. to change it to steam at atmospheric 
pressure. If the water has originally a lower temperature 
or is converted into steam at higher pressure, more B. T. U. 
qre required to accomplish the change. Roughly Speaking, 
if the temperature of the feed and pressure of the steam 
are not given, about 1,000 to 1,100 B. T. U. are equivalent 
tg a pound of steam. Therefore, 1,000 pounds uf steam are 
equivalent to about 1,000 X 1,000 = 1.000.000 B. T. U. 

40. Looking at the question in another light, a pound 
of good coal when burned produces about 1S.500 to 1-1. (K)0 
B. T. U, by the combustion, A boiler of fairly good effi- 
ciency will utilize perhaps 10,000 of these j;i.5O0 B. T. U., 
the rest being lost by radiation, in the production of chim- 
ney draft, and in other ways. From 100 pounds of coal 
theboileriaabte toextract 100 x 10,000= 1,000,000 B.T.U., 
which are eventually given up to the pump, It thus appears 
that 100 pounds of coal and 1,000 pounds of steam are each 
approximately equivalent to 1,000,000 B. T. U. ; for this 
reason, the committee of The American Society of Mechan- 
ical Engineers recommended that the new basis for estima- 
ting duty should be 1.000,000 B. T. U. 

41. The heat-unit basis is now very e.ttensively used and 
is recommended in preference to the others. It may lie 
expressed as follows: 

The duty of a pumping engine is equal to the total num- 
ber i>f fiiot-pouniis of work actually done by the pump 
divided by the total number of heat units in the steam used 
by the pump, and this quotient multiplied by 1,000,000, The 
hi-at units in the steam used for driving the auxiliary 
machinery, such as the air pump and circulating pump of 
the I'oniitfiiser, if one is used, and the boiler-feed pumps arc 
charged as heat units supplied to the pump. 

4'i, The number uf foot-pounds of work done by the 
pump is t(i be fi;imd as follows: A pressure go is 

atiaohcd to the discharge pipe and a vacuum gau 

§ 36 PUMPS. 5>l 

suction pipe, both as near the pump as convenient; then 
the net pressure against which the pump plunger works is 
equal to the sum or difference in the pressures shown by 
these two gauges increased by the hydrostatic pressure due 
to the difference in level of the points in the pipes to which 
they are attached. In case the gauge in the suction pipe 
indicates a vacuum, the sum of the pressures indicated by 
the gauges is taken, but when the water flows into the suc- 
tion pipe under a head, so that the suction gauge indicates 
a pressure above the atmospheric pressure, the difference in 
the two pressures indicated by the gauges is taken. 

43. The number of foot-pounds of work done during 
tihe trial is equal to the continued product of the net area 
C3f the plunger in square inches (making allowance for 
piston rods), the length of the plunger stroke in feet, the 
number of plunger strokes made during the trial, and the 
net pressure in pounds per square inch against which 
the plungers work. 

44. The pressure corresponding to the vacuum in 
inches indicated by the gauge on the suction pipe is found 
by multiplying the gauge reading in inches by .4914, and 
the pressure corresponding to the difference in the level of 
the two gauges by multiplying this difference in feet by 
.434. The number of heat units furnished to the pump is 
the number of British thermal units in the steam from the 
boilers and is to be determined by an evaporation test of 
the boilers. 

Rule 10. — To determine the duty of a pump per IfiOOfiOO 
B. T. C\, multiply the net pressure against li'hieh the plunger 
works^ in pounds per square ineh, by the net area of the 
plunger in square inehes, by the average length of stroke in 
feet^ the total number of delivery strokes made during the 
trial, and by 1,000,000, Divide the product by the total 
number of B. T. i'. supplied during the trial. 

n _ 1 » ^J^^- 00()^(/' ±p-\- S) A L N 
Ur, JJ — J J , 

22 PUMPS. g 36 

where D = duty; 

/^= pressure in pounds per square inch in the dis- 
charge pipe; 

/ = pressure in pounds per square inch in the suc- 
tion pipe, to be added in case of a vacuum and 
to be subtracted in case of pressure above 
atmospheric pressure in the suction pipe ; 

5 = pressure in pounds per square inch correspond- 
ing to difference in level between the gauges; 

A = average effective area of plunger in square 
inches ; 

L = length of stroke of pump plunger in feet; 

N — total number of delivery strokes; 

// = total number of B. T. U. supplied. 

Example. — A crank-and-fly wheel pump has two double-acting water 
plungers, each 20 inches in diameter and 36 inches stroke. Each 
plunger has a piston rod 3 inches in diameter extending through one 
pump-cylinder head. 

During a 10-hour duty trial the total heat in the steam supplied to 
the engine was 35,752,340 B. T. U. and the engine made 9,527 revolu- 
tions. If the average pressure indicated by a gauge on the discharge 
pipe was 95i pounds, the average vacuum indicated by a gauge on the 
suction pipe 8^ inches, and the difference in level between the centers 
of the vacuum and the pressure gauge 8 feet, what was the duty ? 

Solution.— The area of a plunger 20 inches in diameter is 
314. 16 square inches and the cross-sectional area of a rod 3 inches in 
diameter is 7.07 square inches. Since the rod extends through only one 
end of the pump cylinder, the average effective area of the two ends 

of each plunger is 314.16 -^ = 310.63 square inches. 

The pressure corresponding to a vacuum of 8^ inches is / = 8.25 
X .4914 = 4.05 pounds per square inch, and the pressure corresponding 
to a ditferenct in level of 8 feet is .V = 8 x .434 = 3.47 pounds per 
square inch. 

Since there are two double-acting plungers, the total number of 
]>lunger strokes corresponding to 9,527 revolutions is A''= 9,527x4 
= 38.108. 

Applying rule 10, wx* get 

_ I^OOO.IMX) X (95.5 ^ 4^05 + 3.47) X 310. 03 X 3 X 38,108 
^ ~ 35,752.340 

= 102.328,800 ft.-lb. per 1.0<M>.(KH) B. T. U. Ans. 





45, In large pumping plants it often happens that the 
pressure pumped against is either constant or practically 
so. In such a plant a record is often kept for the purpose 
of comparing the performance of the plant from week to 
week or month to month with its former performances. 
The records may be kept in number of gallons pumped per 
pound of coal; in cubic feet pumped per pound of coal; in 
weight of water in pounds or tons pumped per pound of 
coal; or the record may be kept per ton or bushel of coal, 
etc. Duty computed on such a basis is spoken of as grallon 
duty, cubic-foot duty, pound duty, ton duty, etc. ; while 
such a duty is very valuable in showing variations in effi- 
ciency of a given plant at different times, it cannot be used 
as a basis of comparison between the performances of dif- 
ferent pumping plants, and when so used will be utterly 

Instead of keeping the records in terms of quantity of 
water pumped per pound of coal, they may advantageously 
be kept in terms of water pumped per dollar; the records 
then show variations in efficiency in their true light. 


46, The question ** in what terms shall the duty of a 
pump be expressed " depends for its answer on the purpose 
for which it is required that the duty be known. If the 
duty is merely required to be known in order that the per- 
formances of a given pump at different times may be com- 
pared with one another, the duty may be based on coal con- 
sumption, steam consumption, or volume pumped per some 
unit of fuel or money. If, however, the performance of a 
pump is to be compared with that of others working proba- 
bly under entirely different conditions, the foot-pounds of 
work done per 1,000,000 B. T. U. is the only true basis of 

24 PUMPS. § 3« 


47. Small direct-acting pumps for general service have a 
duty of 15,000,000 foot-pounds per 1,000 pounds of steam 
used. Compound direct-acting pumps of 5,000,000 gallons 
capacity in 24 hours should give a duty of 50,000,000 foot- 
pounds per 1,000 pounds of steam used. Large municipal 
pumping engines of 20,000,000 gallons capacity in 24 hours 
have given a duty of 100,000,000 foot-pounds per 1,000 pounds 
of dry steam used by the engine. 

Centrifugal and rotary pumps ^have a duty depending on 
the type of engine used to drive them, and since they 
usually run at high speed and the conditions for economical 
j)erformance are good, an economical type of engine can be 
used and the duty of the combined unit thus made to com- 
pare very favorably with that of the reciprocating pump. 

48. Tests of the duty of pumps and pumping engines 
have generally been made when the machinery was in first- 
class condition. It is customary to run these machines 
from i\ months to 1 year after they are installed before 
making the test, the object being to bring all the journals 
into a good bearing condition; also, the piston and all the 
other rubbing surfaces will be much improved by the polish- 
inj; and the working of oil into the pores of the iron during 
mnning. These high duties can only be maintained by the 
elosesl alUMition to every detail by the operating engineer. 
liuliejUor <\ir(is should be taken from both the steam and 
I he Nv.iliT ends of the pumps every week and closely com- 
pared wiih previous indications to see that the highest state 
ol elheieiu y is being maintained within the working parts 
o| t he pump. 


•lt>. When \Uc onU»loiu\v of a pump is spoken of, its 

Wi*i7/J '.'/.,// riVieieiuv is i^enerallv meant, unless stated other- 

*wi8e. This iN nuMsuiid bv dividing the actual or net horse- 

WtM" t»t the ni.uluiu* In its iiulieated horsepower, and the 

otienl, when n\uhiphid by 100. will be the eflSciency 

g :36 PUMPS. 25 

expressed in per cent. Very small direct-acting steam 
pumps have an efficiency of about 50 per cent., the efficiency 
increasing with the size of the pump up to about 80 per 
cent. The efficiency of direct-acting steam pumps and also 
of pumps in general increases with the size by reason of the 
decrease in the ratio that the frictional resistances bear to 
the indicated horsepower as the size of the pipes and pas- 
sages is increased. The reason that the frictional resist- 
ances decrease can readily be seen when it is considered that 
by doubling the diameter of a pipe and keeping the velocity 
of flow the same, the discharge will be increased four times, 
while the surface that the water is rubbing against is only 

50, Large vertical municipal pumping engines have 
shown an efficiency as high as 96 per cent. ; horizontal 
medium-size crank-and-flywheel pumps show efficiencies as 
high as 90 per cent. The efficiency of centrifugal, rotary, 
and screw pumps varies between 40 and ijC) per cent., about, 
depending on the size; small pumps are less efficient than 
larger ones. This efficiency of centrifugal, rotary, and screw 
pumps is the efficiency of the puvip itself^ and not the com- 
bined efficiency of the pump and engine, or motor, driving it. 


51, Experience has demonstrated that for satisfactory 
work the flow of water in the suction pipes of pumps should 
not exceed 200 feet per minute, and it should not be more 
than 500 feet in the delivery pipe for a duplex double-acting 
pump, or 400 feet for a single-cylinder double-acting pump. 

Knowing the volume of water that is to flow through or 
to be discharged from a pipe in 1 minute, the area of the 
suction and delivery pipes can readily be determined. 

The volume of water in cubic feet discharged from a pipe 
in 1 minute is equal to the velocity in feet per minute 
times the area of the pipe in square feet. Then, 

volume in cubic feet per minute 

the area of the pipe = 

velocity in feet per minute 

2f] PUMPS. §36 

As there are H4 square inches in a square foot, 

the area of the pipe in square inches 

__ 144 X volume in cubic feet per minute 
"~ velocity in feet per minute 

Rule 17. — To find the area of a pipe in square inches to 
discharge a giicn volume of iL*ater per minute, divide the 
product of the volume in cubic feet and 144 */ ^^'^ allow- 
able velocity in feet per minute. 

Or. A = -^;-, 


where A — area of pi{)e in square inches; 

r= volume to be discharged per minute; 
V — allowable velocitv. 

When the weight of water is given in jx)unds, divide 
it bv ♦;*2.5 to reduce it to cubic feet; when the volume is 
given in Winchester gallons, divide it by 7. 48 to reduce it 
to cubic feet. 

Example. — What should be the areas of the suction and delivery 
pipes for a single double-acting pump that is to discharge 6,"i50 pounds 
of water per minute ? 

S«.)LL'Ti'»N- — Reducing the weight to cubic feet, we have ' . 

- 1(N> cubic feet. Then, applying rule 17, we have 

144 X 1«*> 
A — — ^— — = 72 square inches 

a-- the area of the suction pi{)e. and 

144 . I'H) 
A ~ .— , — — ^^♦j square inches 

a> tl,' i!' ; 'f t!.'- 'it "ivcry {>!;►<:. The nearest standard nominal sizes 

• •t pijr.- •,' ' •>•• ii-r-l \v..ul'l W- l<>-inch and 7-inch. Ans. 

.I'i. I ;:» v( 1 .. i:y with w'ni« h water will flow through the 
fb-livt-ry j'ij)^ < .f a pump when the area of the water cylin- 
der, tile area of the delivery pipe, and the piston s{)eed of 
the jjfinnp ar*- kn^wn. is given by the following rule: 

Riih* IS. — Multiply the area cf tJic icatcr piston by the pis- 
toji spitti au'l (li:-i'i( thi> prod net by tlw aria of the delivery 

i 36 PUMPS. 27 


Or. • v = -^, 

where t' = velocity in feet per minute ; 

A — area of delivery pipe in square inches; 
a = area of water piston in square inches; 
5 = piston speed in feet per minute. 

Example. — If the water piston of a pump has an area of 12 square 
inches and moves at a speed of 100 feet per minute, what will be the 
velocity of the water in the delivery pijKj if the latter has an area of 
2 square inches ? 

Solution. — Applying rule 18, we get 

12x100 _.^. . , 

V = ^ = ^^^ f^- P^r mm. Ans. 


1. The plungers of a center-packed double-acting duplex pump 
are 20 inches in diameter and the plunger nxis are 8^ inches in diam- 
eter. Each plunger makes 45 strokes per minute, the length of stroke 
being 24 inches. What is the displacement in cubic feet \^r minute ? 

Ans. 38«5.69 cu. ft. 

2. In the above example, if the pump delivers but 300 cubic feet 
per minute, what is the slip ? Ans. 6.1) per cent. 

3. Approximately, what horsepower will be required to deliver 
60 cubic feet of water per minute, the total lift being 470 feet ? 

Ans. 70.3 H. P. 

4. What is the probable horsepower required to deliver 3,500 gal- 
lons of water per hour against a pressure of 115 pounds per square inch ? 

Ans. 5.57 II. P. 

5. A pump driven by a 25-horsepower engine is to discharge 
60 cubic feet of water per minute. How high may this water be lifted, 
approximately ? Ans. 154 ft. 

6. Approximately, how many gallons of water per hour can a pump 
driven by a 30-horsepower engine deliver at a height of 65 feet ? 

Ans. 1,278.8 gallons. 

7. Approximately, against what pressure can a SO-horscpower 
pump discharge 2,500 cubic feet of water per hour ? 

Ans. 77 lb. per sq. in. 

I be the 
JiK. &»&.■■»«;. 

aad Uw k^ctb o< atfwfee M « Jt^^ fc«wr My gJT mi ■< wsur per 
p taexpecSBd laddHwar H it Hikes a stnkesper 
Am. 174»pLperhr. 

Maun pwnp hariag a plnnger T lacA^ jinttimrtiT 

Aas. 1J*.T gaL per Kna. 

It- If the pwtoa cpecd is W feet jii i iiiiiiiili mil itn h ii^rli of sUDke 

t fact, lufv many «trtdc« prr mioMte vill tbe pw>^ nuke r Aas O. 

U. CalmLiie the mtniraum dtatnewr «< tbettcampiBMaforaptMtp 

luvbiK a iriuciKcr 12 iixtie« In dtamcicr. ihe [WU Maire to be psnped 

•■[■liut befnx 175 puuads per sqture iadi and the arailaMe cUun 

[frn«ur« l(iO|i(]undiiper aqiuircinrh. Abs. l&Kin. 

U. Wfi4t U the duty per 100 pounds at cc«l al a pntnp that niaes 

awMMNt p^iunili of water 1S% feet and requires llti ponwtsaf coal twpcr- 

f'jrm ilu! ..jtcrallun ? Am K.sao.OOO ft.-Ilv 

in. It in.Olft pounds (if Bteam ure cunsumed by a pump ia lifting 

l;H)»,«m khIW* (if water IM feet, what is tile duty per 1.000 pnundsof 

dry Mtiim ' Ans. 75,000.000 fl.-lb. 

1(1 AiI>iul)IPKiIiii|[|iump has nstmke of 40 inches: tlie diameter oi 

lh» pluiiifrr in ti inrlies and llie dlameler of llie piston rod. whidi 

•iUflda litruURh ■>«• [ium|v<-ylinder head, is St incb«. Uuringa li-hoor 

"* • li'lal hpat Bupplicd to the engine waa 47.S53.QOU B. T, U. 

■ made 28,ai» •irwkTO. Wliat was the duly of the pump 

liT, I'. If thir nve rage pressure indicated by the ffaugeon 

iiiiiiiiK, ilio jvcnige i-acuum indicated bya 

.11 l»>. iijid ihr iliflerence in level between 

11(1 pressure gauge was III feet ? 

Ans. a3.Ar>S.I!3fl.-tk 


1 rifljvtrv pipes for a slagle- 
.,...r««ler per minute. 
I SiK-lion pipe. I30,« s»). In. 
' 1 iflivery pipe. 60.18 sq. In. 
ijiiip .1 spet-d of 83 feet 
1 " iH W the velocity of tbe 
..11 jrt:a of li square inches? 
Aii£. M0.3 ft. per mia. 

§36 PUMPS. 29 



53. Introduction. — The service for which a pump is 
required determines its general type, that is, whether it is 
to be a plunger pump, a rotary pump, a centrifugal pump, 
or a screw pump. 

54. Reciprocating Pumps. — The various types of 
reciprocating pumps are selected when high efficiency is 
required and a fluid for which they are suited is to be 

55. Rotary Pumps. — The rotary pump is chosen when 
the fluid to be pumped is water holding in suspension large 
masses of soft material. It is much used in paper mills 
for pumping the pulp from one stage of its manufacture to 
another. Rotary pumps are small and occupy, relatively, 
but little space for their capacity; they are also light, 
simple, and inexpensive, but are low in efficiency and are 
short lived, particularly if the material pumped contains 
much sand or other grit. The rotary pump is used with 
good success on some steam fire-engines, where light weight 
and simplicity are more important than high efficiency. 

56. Centrifugal Pumps. — Centrifugal pumps are used 
where large volumes of water are to be lifted to moderate 
heights. They are also well adapted for pumping large 
quantities of dirty water, and, hence, are also much used for 
dredging and for sewage pumping. The efficiency of the 
centrifugal pump is low, but it is extremely simple and 
occupies comparatively little space for its capacity. Like 
the rotary pump, it has" no valves and the flow is con- 
tinuous. It is less affected by sand and grit than is the 
rotary pump. Neither the rotary pump nor the centrifugal 
pump requires much, if any, foundation. 

67. Displacement Pumps. — Under the head of dis- 
placement pumps may be classed the pulsometer, which has 

30 PUMPS. §36 

no running parts. This type of pump is well adapted for 
pumping all kinds of gritty water and is used for sinking 
and contractor's purposes. It is very simple in construc- 
tion, low in first cost, and is not liable to get out of order. 
The class of pumps known as air lifts are principally used 
for artesian-well service ; they require an air compressor for 
operation, but the apparatus itself is simple and low in first 

58. Herew Piiinps. — Screw pumps are adapted for the 
handling of thick liquids, such as hot tar, pitch, paraffin, 
soap, etc. They have a uniform discharge and occupy small 
space; a much higher efficiency is claimed for them than 
for rotary or centrifugal pumps. 



59. The reciprocating pump is, in general, the most 
efficient and hence the most common pump. It is built in 
a large variety of designs to suit different conditions and 
varies in size between very wide limits. Reciprocating 
pumps may be classified in accordance with the service for 
which they are intended as boiler-feed pumps, general- 
service pumps, tank or light-service pumps, fire pumps, low 
steam -pressure pumps, pressure pumps, mine pumps, sink- 
111^^ pump^, ballast pumps, wrecking pumps, deep- well 
pumps. -«\vai;e pumf)s, vacuum pumps, power pumps, 
iininicipal pumping engines, etc. 


()(). lioilor-food pumps are used for supplying steam 

i"'il(i~> wiili their necessary water supply. For low pres- 
■-111 (^ tiny are usually made of the [)iston pattern or the 
'li-i'l' p.K kf.] pi ini;,^ei- patterns. The cylinders are generally 
'^la-- hiird; the valves are brass or hard composition, with 

§ 36 PUMPS. 31 

composition springs and guards, and the pumps, hence, are 
suitable for handling hot water. For pressures above 
135 pounds the outside-packed plunger type is preferred. 
Boiler-feed pumps are made both vertical and horizontal 
and for pressures from 60 pounds to 300 |X)unds per square 
inch. They vary in size from those having water plungers 
1 inch in diameter to those having plungers 10 inches in 
diameter. The single-cylinder type is much used for boiler 
feeding, but, perhaps undeservedly, they have not the repu- 
tation for continuous action under all circumstances that is 
given to the duplex pump. Power pumps are often used 
for boiler feeding. 

61, Whenever possible the boiler feeding apparatus 
should be in duplicate, so that the stoppage of one set will 
not affect the running of the plant. This end is generally 
secured by installing both a pump and an injector, each 
having a capacity sufficient for the needs of the plant. 

62. Steam-driven crank-and-flywheel pumps are occa- 
sionally used, but they are open to the serious objection that 
they cannot always be run slow enough to suit the demand 
without stopping on the centers. In very large electrical 
installations, the electrically driven power pump is the most 
economical and satisfactory arrangement. Mills and fac- 
tories often use the two-throw power pump having a mov- 
able crankpin, by means of which the stroke and hence 
the quantity of water pumped can be adjusted to suit the 
requirements. By this means a constant supply of feed- 
water equal to the demands for steam can be obtained, 
which is superior to the practice of pumping large quantities 
of water into the boilers at intervals. Boiler-feed pumps 
should not be required to run faster than 100 feet per 
minute piston speed. The velocity of water through the 
suction pipe should not exceed 200 feet and through the 
delivery should not be more than 400 feet. If the pipes are 
long or fitted with elbows, the velocity should be correspond- 
ingly decreased. 

H. S, y,^ii 

32 PUMPS. § 36 

63. In determining the proper capacity of a pump for 
boiler feeding, the pump should be selected in reference to 
the amount of steam the boilers must supply. This is rarely 
only the amount used by the engine ; in fact, in many indus- 
trial establishments much more steam is needed for other 
machinery than for the engine. Hence, it is best to always 
base the estimate as to the amount of water required on the 
maximum capacity of the boilers. 

64. The maximum water consumption may be estimated 
in pounds per minute by one of the following rules, which 
hold good for average practice under natural draft. It will 
be observed that no rule based on the so-called *' boiler 
horsepower " is given, for the reason that this is too variable 
a quantity to place any reliance on. 

Rule 10, — For plain cylindrical boilers multiply the prod- 
uct of the length and diameter in feet by ,18. 

Ilule SO. — For tubular boilers multiply the heating sur- 
face in square feet by ,06, 

llule SI. — Multiply the grate surf cue in square feet 

by L 7. 

Kule 22. — Multiply the estimated coal consumption in 

pounds per hour by .17. 

Ckk Whenever possible the feed-pumps should be located 
in the boiler room, sous to be directly in sight and in charge 
of the l)oil('r attendant. In very large installations it is com- 
mon to arrani^c the pumps in a separate pump house, they 
Ixini^^ lh<n in charge of one of the assistant engineers, the 
l)"il(.*r aii(.*ii(l:ints reticulating the supply to each battery by\'«'S in the fcc(lj)ipi's. 

<;i:\fi:al-si:hvic K pi'mps. 
(W>. (;<*noraI-s('rvic<» pumps are a line of pumps placed 

"!i tli«- in.irkci by many of the pum[) builders to be used 
to! .iiiy scrNJcc where tlie watrr pressure does not exceed 
I.'io j.. )niifls. They are <4:enerally of the plunger type and 
arc i)uilt in sizes varyini^; from those having a 4-inch to those 

§ 36 PUMPS. 33 

having a 16-inch plunger, and of a capadty varying from 
100 gallons to 2,500 gallons per minute. They may be used 
for any service such as boiler feeding, fire, hydraulic elevator, 
or anywhere where the pressure to be pumped against is not 
greater than the limit stated. 


67. Tank or light-service punii>s are of the same gen- 
eral form and interior construction as general-service pumps, 
except that the plungers are much larger in proportion to 
the steam cylinders, equalling or exceeding them in diam- 
eter. Such pumps cannot be used to feed their own boilers, 
but they are sometimes fitted with an attached pump for 
this purpose. Light-service pumps are commonly built of 
the same capacity as general-service pumps, but can only 
pump against low pressures. 


68. Fire punii>s are most frequently of the duplex 
•double-acting type with a ratio of area of steam cylin- 
der to water piston of about 4 to 1. The duplex engine is 
chosen for this service on account of its simplicity and the 
peculiar adaptability of its motion to the high speed that is 
sometimes recjuired in this service. A fire pump is fre- 
quently fitted up with a number of nozzles for hose 
connection. It should have relief valves, air and vacuum 
chambers of large capacity, steam and water gauges, 
priming pipes, and all the necessary valves. 

Fire pumps, as implied by the name, are intended for use 
in case of fire, and are required to throw a large volume of 
water at high pressure. 


69. Ijow-iiressure steam pumps are pumps intended 
for localities where only a low steam pressure is available, as 
in apartment houses, public and private buildings, etc., 

34 PUMPS. §36 

in which the pressure at which the steam heating system is 
worked does not exceed 5 to 10 pounds per square inch. 
The ratio of cylinder areas is about 9 to 1, the steam cylin- 
der being the larger. Otherwise they are fitted up similar 
to pumps for general service. In some cases a hand power 
attachment is provided so that the pump can be worked by 
hand when the steam pressure is down. 


70. Pressui-e puin|>s are designed especially for use in 
connection with hydraulic lifts, cranes, cotton presses, test- 
ing machines, hydraulic machine tools of all kinds, and 
hydraulic presses, also for oil pipe lines, mining purposes, 
and such services as require the delivery of liquids under 
very heavy pressure. These pumps are invariably of the 
outside-packed plunger type and generally have four sin- 
gle-acting plungers working in the ends of the water cylin- 
ders, the latter having a central partition. The water 
valves are contained in small chambers capable of resisting 
very heavy pressures and ingeniously arranged for ready 
access. All materials used in the construction of the water 
end must be first class and suitable to the pressure used, 
which ranges from T50 pounds per square inch to 1,500 
pounds per square inch. The water ends of these pumps 
are frequently made of hard, close-grained composition for 
medium pressures, and of steel castings for the heavier 


71. Perhaps no other class of pump requires as much 
experience and skill to select as the mine pump. The reason 
for this is the wide variations in service, conditions of opera- 
tion, head <;r pressure to be worked against, and the destruc- 
tive nature of the water to be pumped. Nearly all the 
pumps at [)resent installed are placed entirely below the sur- 
face. In former times the Cornish, or bull, pump was the 
favorite, hut it is today abandoned for the more compact 

§ 36 PUMPS. 35 

and less expensive modern mine pump. The water end of 
the modern high-pressure mine pump may be described as 
having outside-packed plungers; strong circular valve pots 
independent of one another, but bolted to the working 
chamber, to the suction and delivery pipes, and to one 
another. Frequently the whole inside of the water end of 
the pump, from the suction nozzle to the discharge flange, is 
lined with wood, lead, or some other acid-resisting sub- 
stance. Sometimes the entire water end is made of an acid- 
resisting bronze. Unless the service is light the outside- 
packed plunger pump is recommended for mine work; the 
valves should be preferably metallic valves in separate pots 
or chambers. Whether the pump shall be simple, com- 
pound, or triple expansion depends much on the price of 
fuel. In the anthracite coal regions the compound mine 
pump is now very common for sizes as small as 1,000,000 
gallons in 24 hours, and they are invariably compounded 
for larger sizes, while the triple-expansion direct-acting 
pump is found in several of the mines. 

72. Compound crank-and-flywheel high-duty pumps 
using the steam expansively have but recently been installed 
in the coal mines; in the iron and copper mines, where the 
cost of fuel is very high, the highest types of pumping 
engines have long been used. 

73. When the larger types of high-duty pumps are used, 
the mine workings are generally so arranged that all the 
water runs to one large basin or sump near which a cham- 
ber of sufficient size is cut to contain the pump, which is 
surrounded and protected by suitable devices to maintain it 
in a high state of efficiency. 

74. In many mines, strength and simplicity are the con- 
trolling elements in selection, for the reasons that many 
mines are compelled to use a large number of medium sized 
pumps and, for commercial reasons, use only one man whose 
business it is to make the rounds of the various pumps, giv- 
ing each one but a few minutes' attention in a day. They 
generally have to stand rough usage, and the water pumped 

36 PUMPS. § 3ti 

is of such a corrosive quality that repeated renewals <»f 
parts of the water end are absolutely necessary. After 
heavy rains or other causes of floodinp^, the pumps are often 
required to run for days completely submerged and must 
pump both themselves and the mine dry. It can be readily 
seen that a pump for such service must be strong, simple, 
ready of access, and all of its parts of such construction that 
they can be readily taken apart or renewed. 


75. Sinking: pumps are used in sinking or deepening 
mine shafts. There is little choice in their selection ; gen- 
erally speaking, they should be simple, strong, and capable 
of working in any position. The valves should be of the 
simplest possible construction and accessible for renewal 
with a minimum of labor and time. The valve motion 
should be simple and protected from dirt and drippings. 
They are regularly built single cylinder and duplex and are 
steam or electrically driven. With electric sinking pumps 
the protection of the electrical parts must be very complete. 


76, BalUist and wrecking: pumps are principally con- 
fined to the marine service. The ballast pump is used on 
steamers havinjj^ an extensive system of water ballast; also, 
for handlini;- jK'troleum in bulk on oil-tank steamers. It is 
(lisiinciivfly a sj)ecial pump. The wrecking pump has a 
soincwlial \vi(K'r spluM'e. As its name implies, it is used 
j)riii( ipally by wrcckini^ companies on the Atlantic and 
Pacilic (oasis and alon«^ the Lakes and is constructed with 
partic ulai" rdcrcncH' to reh'ahility, portability, and general 
t'lticinuy. It is widl adapted to other services requiring 
the delivery of larjj^c volumes of water within the range of 
lit I by suction, ft has no forcinj^ i)ower, the water being 
merely deb\ered over tlie top of the pump, and it is single- 
act in j^', tlic water piston being fitted with valves. It is a 

§36 PUMPS. 37 

very light form of pump in proportion to the work it will do, 
is simple, durable, and not liable to derangement or break- 
age. It is also well adapted to drainage and irrigating 


77. I^eep-'well pumps, like sinking pumps, give little 
field for choice except in the pump-driving mechanism, 
which is as varied as the agent available to operate them, 
the principal agents being steam, electricity, gas, and wind- 
mills. The pump is usually a lifting pump having a bucket 
packed with numerous hydraulic leathers and working 
within the casing; it is usually given a very long stroke. 
These pumps do not handle gritty water successfully. 
Probably the best practical solution of the deep-well pump 
problem will be found in the air lift, which in principle and 
operation is quite simple. 


78. Sewage pumps are built in various types. When 
the lift is low, which condition is most common in sewage 
disposal, the centrifugal pump is the cheapest to install, but 
when economy and efficiency are important factors, the cen- 
trifugal pump must give place to the more expensive but 
more efficient reciprocating pump. Probably the largest 
single pumping engine ever constructed is the sewage pump 
for the city of Boston, which has a capacity of 70,000,000 gal- 
lons in 24 hours. 

79. It will readily be seen that the selection of a type of 
sewage engine will depend much on the capacity of the 
installation and the price of fuel delivered at the station. 
The principal characteristics of the sewage engine are in the 
valves, which must be provided with very large ports to 
allow fairly large objects to pass through the pump without 
obstructing its valves. The valves are frequently made in 
the form of large leather-faced doors or flap valves, giving 

38 PUMPS. § 36 

nearly the full area of the pipe. The sewage pump does 
not differ in other respects from pumps for general service. 


80, Power pumps are among the oldest styles of pumps, 
and may be developed by driving any type of reciprocating 
pump by other means than the use of a directly attached 
steam, gas, or air cylinder. Power pumps are very often 
geared or belted and with the increasing application of 
electricity the electric power pump is coming into more 
extensive use. 

81, Power pumps may be used for any service and are 
frequently found in municipal water works, being often 
driven by a turbine or a Pelton waterwheel. In large 
electric-lighting, heat, and power plants, the power pump is 
much used for boiler feeding; in this case the pumps are 
usually triplex, giving a* steady flow of water, and are driven 
by electric motors, the current being furnished by the main 
generators. This is probably the most efficient and econom- 
ical boiler feeder that has been developed. 

82, The power pump is used quite extensively in the 
mines. An electric motor being the driver, the system 
admits of many various sized pumps being placed at the 
different sumps throughout the mines and driven by one 
lar^e and economic al generating unit at the surface. 

S.*^. Tlu^ selection of a power pump in preference to 
other types (le{)ends on (^)nclitions that, to some extent, may 
l)e gathered tpoin the al)ove api)lications; the choice, how- 
e\('r, (lepeiul> iHueh oil the kind of power available to run 
the inaehine. Where water-power is available, either for 
l; earing- chreetly to the pump or for generating electric current 
t')dri\c the pump at a remote distanee, the power pump may 
ad\ antaL^coiisly \)v. ehosen. It should he remembered in this 
eoiiiKM t ion that a steam pump should be installed to take 

§ 36 PUMPS. 39 

care of the teedwater when the main engines are stopped 
and no current is available for driving the power pump. 

84, In private houses, hotels, office and public buildings 
the electric-power pump is a favorite, and to avoid the noise 
of gears the reduction in speed is made by friction drives of 
various types; rawhide gearing is also used to some extent. 
The construction of the water end of power pumps does not 
differ from other pump constructions for the same service. 


85. While the municipal pumplniir en^irine may be of 
any size and capacity, and while some of the pumps already 
discussed, as the general-service and power pump, may be, 
and are, frequently used, the term usually implies the 
highest type of pumping engine that can be constructed as 
regards economy and efficiency. The refinement is more 
exacting as the capacity of the pump increases. For small 
municipal pumping engines, say of 2,000,000 to 5,000,000 gal- 
lons capacity in 24 hours, the compound and triple-expansion 
direct-acting engine is used, the degree of expansion depend- 
ing on the price of fuel and the capital available for the 
investment. For installations of from 5,000,000 to 20,000,- 
000 gallons capacity, the high-duty direct-acting engine, 
that is,, the direct-acting engine with high-duty attachment, 
and the crank-and-flywheel engine are rivals for the instal- 
lation; while for large municipal pumping engines above 
*/iO,000,000 gallons 'capacity in 24 hours, the vertical triple- 
expansion condensing three-crank single-acting, or differ- 
ential, plunger beam type may be, said to have no equal. 
With the latter type of engine a duty of 160,000,000 foot- 
pounds of work per 1,000 pounds of steam used by the engine 
is now common. Steam pressures of 175 pounds are com- 
mon, while the number of expansions are as high as 2*2 to 26, 
and every reasonable device known in the art of steam 
engineering is used to the end of breaking records in secur- 
ing a high duty. 

?v\rps. § 30 

VAC rnf 

86w Vjioaom pamp-iire rhietlj a^ed in connection with 
yz c rArZL5^T< ^r. i -r-'.r. o -.denser?. A vacuum pump is 
:r. rej.l::y ^r. Jlit r -~r. it beir^ ased for pumping air out of 
cl- -je^i ve^ssels There are iwo general types of vacuum 
pumps, wz::t. ^re dry v^ftcaiun pmnpi^ or pumps that 
haridle a:r - t.'.j, 3.t. i ^wet vmcanm piun|iis« or pumps that 
handle r- rh :t:r i-«i water Vacuum pumps are also used 
in s-r-me mar.uraoturir.z • perativ^ns where a high degree of 
vacuum :> reviuire^i. bein^ txsed in connection with the 
vacuum psins : :und :n su^ar houses, with glycerin pans, 



87. The re'^ti^e merits ot the two types of machine for 
a particular size, -ther c^nditi'-ns t^ing equaK are such that 
it is a very difficult matter t ^ decide which type is superior. 
For pumpini^ small quantities ot water, say up to TOO gallons 
per minute, and in Kvali ties where cc»al is not expensive, the 
direct-acting i»ump. either simple or compound, should a g«HV. investment. The t^bjection to the direct- 
act in;^ pump t'T lari:e sizes is its waste of steam as 
compared with the cra::k-a:.d-r1ywheel pump: it has an addi- 
ti'-nai •»l»jecti'!i that is < rnetimes arvTued against it, which 
i< y : ';-y\ c; .\-. Tiiis lierect revluces its economical per- 
t-r::..:!!' - ::: :::,:: :■ rruiiire^ >• ine steam to fill up the space 
• : : : * :r;. '.eie s:r ke. hi:t since the incomplete 

-:'^ k' - • : ':: ,C-- ^ c :ripressi«>n. the compressed 

. >: ; :. ..:!\*.: ::.c space before fresh steam 
. •' :. - • : i: ti.r !'« :< :.<>: S'» verv iireat after all. 
' k: _: : •:: e< ti.r cj.r'acity of the machine some- 
i * • ::i:r n types • f liirect-acting pumps, the 
-*'<'ir:i > :. : •.v'-rk'-i e\|»ansively : '\n compound and triple- 
<-xp.i!>' •:. :.;::::•-. --ine de'>:ree <»f expansitui is obtained, 
ii^Mal!/ :i '•::!•• w.^rr than the ratio (>f hii^li- pressure cylinder 
to I'-w-pr'-- ii'- . y!:::>ler. By nuikini:' the reciprocating parts 



§30 PUMPS. 41 

heavy and running the pump at some fixed minimum speed, 
an early cut-off can be effected in the high-pressure cylinder, 
the balance of the stroke being completed by the inertia of 
the reciprocating parts; in this way an increased degree of 
expansion is possible. 

Another method of securing a considerable degree of 
expansion in the direct-acting pump is by means of the high- 
duty attachment. With the same degree of safety the speed 
of the direct-acting pump is very much less than is possible 
\vith the crank-and-fly wheel pump. The direct-acting pump 
in which any attempt is made at economy will occupy quite 
as much space as the crank-and-fly wheel pump of the same 
capacity, but the direct-acting pump is lower in first cost 

88, Probably the most objectionable feature of the 
crank-and-flywheel pump, which is an inherent one, is that 
the velocity of discharge varies throughout the stroke. This 
is due to the fact that while the flywheel rotates at a uniform 
speed, the pistons and plungers move with a variable speed, 
varying from zero at the beginning of the stroke to the 
maximum speed near mid-stroke and then decreasing to zero 
at the end of the stroke. This variation in velocity pro- 
duces shocks, and hence requires the water end of a flywheel 
pump to be of heavier construction than a similar end for a 
direct-acting pump. The valve area of a flywheel pump 
requires to be considerably larger than for a direct-acting 
pump, not only because of its capacity for higher speeds, but 
also because the velocity of the plunger, when the connect- 
ing-rod is at right angles to the crank arm, is somewhat in 
excess of 1.57 times the mean velocity of the plunger. In 
addition to the greater valve area and strength required in 
flywheel pumps, it is necessary to use some means to reduce 
the shocks to the mechanism and parts of the pump. This 
is accomplished by providing large air chambers, preferably 
one over each deck for high pressures; for very high pres- 
sures and long columns of water, an alleviator is necessary. 

89. The main advantage of the crank-and-flywheel pump 
is its economy, which, in turn, is due to the fact that the 

42 PUMPS. § 36 

steam may be expanded to any permissible degree; it also 
readily admits of all the refinements known of securing high- 
duty performance, and with a proper arrangement of details, 
it can be made quite as safe as ordinary machines. For 
extreme high duties the crank-and-flywheel pump is always 
chosen, and to reduce the shocks due to a variable discharge 
a favorite type is the three-crank machine. The combined 
delivery from three plungers is tolerably uniform and the 
arrangement readily lends itself to the extremely economical 
triple-expansion condensing engine. 

90. The crank-and-flywheel engine is more expensive 
than the direct-acting machine, and when high degrees of 
expansion are used occupies considerably more room. It is 
generally more complicated, but is more accessible, except in 
such cases as where an effort is made to minimize space, 
when by making the engine back-acting it is liable to become 
quite inaccessible. 

91. The piston speed of direct-acting pumps rarely 
exceeds 100 feet per minute, while the piston speed of crank- 
and-flywheel pumps is commonly 300 feet and sometimes 
400 feet. With pumps of the controlled-valve type, piston 
speeds of 500 feet are reached. This difference in the piston 
speed of the direct-acting and crank-and-flywheel pumps 
shows that they must be compared on the basis of water 
delivered rather than on the relative size of similar parts. 

{}2. Even for very small sizes, the crank pump is sure in 
its action and is not liable to get out of order; this cannot 
be I lainied for some of the single-cylinder direct-acting 
piunps having steam-thrown valves. The crank pump is 
limited as to its slowest speed, however, since the speed must 
he sufficient to store energy enough in the flywheel to carry 
the (M'ank over the dead centers. This objection can be over- 
come to a great extent by using the by-pass, which allows 
part of the water to be returned to the suction, thus decreas- 
ing the work on tlie pump. 


(PART 1.) 



1. Deflnitioii. — The term elevator is applied to that 
class of hoisting machinery in which a cage, cab, car, or plat- 
form is raised and lowered between fixed stops or landings. 

2. Principal Parts. — In all complete elevators the fol- 
lowing principal parts are easily distinguished : 

1. The motor. 

2. The car (cage, cab, or platform) and its principal 

3. The devices transmitting power from the motor to 
the car. 

4r. The counterbalance weights and their guides. 

5. The controlling devices. 

6. The safety devices. 

7. Accessories. 


3« Various kinds of motive power and, consequently, 
motors are used to run elevators. In practice, the classifi- 
cation of elevators is made according to the motive power 
used. The most generally accepted one, which is also the 

For notice of copyright, see page iinnu'iliiitcly foni>\ving the title i>agc. 

2 ELEVATORS. § 37 

one that we shall adopt, is as follows: Hand-power eleva- 
tors^ belt elevators, steam elevators, electric elevators, and 
hydraulic elevators. 


4. It is evident that elevator cars must be different for 
various purposes. All of them, however, have a platform 
upon which the load rests, and with few exceptions, as 
in sidewalk elevators, two upright posts connected by a 
erossheacl to which the ropes are attached. Each upright 
carries two g^uide shoes, one on top and one on the bottom, 
which fit over the g^uides. The latter consist either of 
hardwood strips of square cross-section or bars of T iron 
carried up inside the hoistway and attached to suitable sup- 
ports. According to the location of the elevator shaft in 
the building and the accessibility of the guides, they are 
placed either in the center of two opposite sides of the shaft 
or in two diametrically opposite corners, necessitating the 
upright posts of the cars to be placed in like manner with 
reference to the platforms. In the first case they are called 
side-post elevatoi-s; in the other case, eoriier-post ele- 
vatoi-s. The guide shoes are usually of cast iron, and in 
the case of iron guides are lined with Babbitt metal. 

For freight service the cars are of the simplest kind; they 
are generally made of wood with iron fixtures and bracings. 
For passenger service a complete cage is built upon the 
platform, preventing any possible contact of the passenger 
with the hoistway. Passenger cars are now mostly btiilt 
wholly of metal, though many wooden ones are in opera- 
tion. Various styles of cars are shown in subsequent 


5, Various transmitting devices are used with different 
kinds of motive power. Hydraulic elevators and a certain 
electric elevator have peculiar transniittin*^ devices of their 

g 37 ELEVATORS. 3 

own, which will be described in connection with these ele- 
vators. All belt and steam elevators and the majttrity of 
hand and electric elevators are of the driiiii>e, that is, 
of a type in which the transmitting devices include a drum 
and rope. All these elevators, therefore, have certain pecu- 
liarities in common, which are pointed out beforehand to 
avoid repetition. 

6. Bide Travel of Roi»es In Driiin Klevntors.— An 
inherent feature of the rope-and-drum drive is the deflection 
of the rope as it winds upon the drum. Let D, Fig. 1, be 
the winding drum and S the nearest sheave from which the 


rope passes on to the car. It is plain that only at a certain 
position of the car the rope runs over the sheave exactly 
straight; in all other posLiiiuis it must be guidt-d into the 
sheave. If the distance between the drum and the nearest 

4 ELEVATORS. § 37 

sheave i> g^reat. as, tor instance, when the ro|)e passes 
straiirht up fr-'m a drum hx-aied at the foot of the hoistway 
t«> an "Vc-rhead sheave, the deflection measured by the 
angle «/. Fig. 1. is but small and readily taken care of by 
the dc-j'th »>t the gr«,K^ves in either sheave or drum. But 
if the distance is small, danger exists that the rope will jump 
the gr.H.ves fi the drum and •'ride" on itself, which may 
evident I V cause accident. Such small distances between 
the drum and the nearest sheave are frequently unavoidable. 
Thus, in the case sh«'wn by Fig. '2, where it is required that 
the r-^jH*s«»t S'th the car and the counterweight shall run 
within tlx- h. •istway. the hoisting rope must be led over an 
Idler > very near the drum A and the counterweight rope, 
in the case >h«'\vn, will surely ** ride " if no provision be made 
against it. Those idlers are. therefore, so mounted on their 
shafts that they can t'»How the ropes as they wind upon and 
unwind from the drums. Such a traveling idler is some- 
times sjx»ken ot as a vlbnitor. In most cases it is found 
suflicient to mount the idler I«x^selv on a smooth shaft and 
to rely on the pressure •>! the rope against the sides of the 
griv»ve in the idler to shift the latter along. That careful 
lubricati' »n is essential to the proper working of this arrange- 
ment is evivient. 

7. The cniisiant chafing of the rope against the sides of 
the idler gn»«ne, which is unav.»idable in the arrangement 

; mentioned. i< an objection, and if considered of suffi- 

it influence •>!: the life of the rt>px*, is avoided by giving 
; idler a p'»si::ve motion in the direction of its shaft. 
fs. 3 and 4 sh- w :w. w.iys of acc«;'mp>Iishing this. 
'!n Fig. :J. the :\\r shafi .i is c- r.nected to the drum shaft 

a chain aiui >:'r«ckt: wheels, :he hub of the sprocket 
eel fi on the :»iUr si:af: i>ei:;5C a r.::: ritting over a square 
:ead cut on liie <i:art .uui beinj^ '::eld fr«^m moving side- 
ie. This causes the shaft t.^ niv've in the direction of its 
S, a feather preventing:: it from rotating. The idler c 

IS loosely on the shaft, but moves back and forth with it, 

to collars on the shaft. 



8. In the arrangement shown in Fig. 4, the chain connec- 
tion is dispensed with. The idler shaft a is threaded but is 
held stationary, and the idler hub is a nut, so that while the 
idler revolves by the friction of the rope it travels back and 
forth. Since there is no positive connection between the 
drum shaft and the idler shaft, any slippage of the rope on 
the idler will bring the arrangement out of adjustment. 
For this reason the following plan for automatic readjust- 
ment was adopted by the Otis Elevator Company. 

The idler is provided with stop screws c and c' that 
engage at the end of the travel with fixed stops i/, d on the 
shaft supports. If for any reason slippage has occurred and 
the idler lags behind, it will be ahead of the rope on the 
following return trip and engage the stop on the shaft 
support before the drum comes to rest; the idler being thus 
prevented from turning, the rope will slip until the drum 
stops; on the following trip the idler will leave the stop at 
once and, thus readjusted, will follow the rope correctly. 
To allow of a fine initial adjustment, the idler has eight 
spokes, each drilled and tapped to receive the screw 
stops c,c'. 

H. S, V.-ia 


9. Ahmrptlon of Tlbntlloo Dne to Gearlnsr.— Ajf 

inherent feature of all drum elevators is a certain amount of 
unpleasant vibration transmitted from the gearing through 
the dnun and hoisting rope to the car. This vibration is 
especially noticeable in spur-geared machines; but it also 
exists in worm-geared ones, owing to the fact that a certain 
amount of backlash, be it ever so httle, always exists. To 
reduce these vibrations to a minimuoi, elastic buffers, gen- 
erally of rubber, are sometimes interposed between the 
drum and the next adjacent gear. Fig. & shows a way in 

which this may be done. The gear-wheel a is keyed to the 

, shaft, while the drum ^ is loose. The gear-wheel drives the 

4nim by means of drivers c, c, which are cast in one with 

^e gear-wheel. These drivers, instead of butting directly 

[ainst metallic surfaces of the drum, butt against rubber 

)cks, or buffers, li.J. These buffers must be given a cer- 

> amount of initial tension, which is accomplished by 

! tie-bolts f, t that tie the drum and the gear-wheel 

Aber. The end view shown in Fig. 5 is taken between 

! gear-wheel a and the drum b, which accounts for the 

: that while the drivers e, c are seen, the gear-wheel is 

The tie-bolts must have jam nuts or some other 

nut-locking device, which should be examined 

tsionally to see if the bolts have become slack. 





10. In any elevator, the weight of the car and its fix- 
tures is constant, and hence is easily counterbalanced to 

any extent desired. The sim- _^ ^_ .. —^ 

plest way to do this is to attach '^^ ClJkl^ C!> 

another rope, besides the hoist- 
ing rope, to the car, leading 
this second rope over one or 
more overhead sheaves and 
suspending from it the counter- 
balance weight, or the coun- 
terwelght, as it is generally 
called, as shown in the dia- 
grammatic illustration given 
in Fig. 6. In order that the 
car may descend when empty, 
the counterweight must, when 
so attached, always be less 
than the weight of the empty 
car with its fixtures. ' Evi- 
dently, with such an arrange- 
ment, no power is needed for 
the down trip of the car, while 
on the up trip, the motor must 
develop enough power to raise the maximum load, plus the 
unbalanced weight of the car. In all types of elevators in 
which the motor furnishes power only on the upward trip of 
the car, as in hydraulic elevators, for instance, the arrange- 
ment shown in Fig. 6 is the only method of counterbalan- 
cing available. 

11. If in an elevator the power can be applied during 
the down trip as well as during the up trip, then not only 
the full weight of the car can be counterbalanced, but also a 
part of the load. An elevator thus counterbalanced is said 
to be overbalanced. This possibility exists in all drum 
elevators, as the motor and drum are reversible. They are, 
therefore, overbalanced, except when other considerations 

Fig. 0. 




I'lyt *xte-- 'Z-i the aTerage load by 

rix-« - '-■ ^"^ crnm and winding^ the 
Z'-.CL I-:- ihat ot the hoisting rope, as 

T-f^rralircin^ :> easilT apparent. If 
:•: ibc aTerage load, no power is 

^ ^ 




n^ ' r]^<i ^.,-J ]^< ♦;.•.» luressary :> >tart the machinery and 


4-1 .1 

,> : 

!l!' ;■!'■,•'' 

wrj: ai^ainst tricti«»iiai resistances. If the load is 

'■^jiiai t'. ti,'- nia\i:inini l^ad and the car is going up, the 
ni''t';r must Jiirni^h [x-wtr enou;>rh to raise the difference 
b<-tu';*h tlif niaxinium and the avtrai2;e load : or if the latter 
i-. on*- -half tii'- inaximnni load, to raise one-half of the maxi- 
niiini l'/a<l. It tlie car is gt.)ing d<»\vn empty, which is the 




other extreme possibility, the motor must raise the counter- 
weight, that is, the weight of the average load. Thus a 
motor can be used of greatly smaller capacity, which means 
smaller size, less weight, and smaller cost. In connection 
with electric drum elevators, overbalancing also tends to 
equalize the current consumption. 

12. By an arrangement somewhat different from that 
shown in Fig. 7, the stress in all the ropes and the pressure 
on the drum-shaft bearings may be diminished. In Fig. 8 




Fig. 8. 

there are shown two counterweights, one attached directly 
to the car and the other to the drum. The car counter- 
weight must evidently be less than the weight of the car in 

10 ELEVATORS. § 37 

order to allow the car to descend when empty; the other 
counterweight is equal to the remaining portion of the ' 
car weight plus the average load. If the car counter- 
weight is, fur instance, one-half of the car weight, 
then the stress in the drum-counterweight rope and the 
hoisting rope is less than in the arrangement shown in 
Fig. 7 by one-half of the weight of the car, and the pres- 
sure on the drum-shaft bearings is less by the whole 
weight of the car, 

13. For high lifts, the weight of the ropes themselves is 
a considerable item, making the counterbalancing change 
for different positions of the car. To avoid this, balancing 
chains having the same weight as the ropes to be balanced 
are used and are hung from the bottom of the car, either 
reaching all the way down to the bottom of the hoist- 
way, in which case the chain must have the same weight 
per unit of length as the ropes, or reaching down only 
to the middle of the shaft and fastened there, in which 
case the chain must have a weight per unit of length double . 
that of the ropes to be balanced. This method is indicated ^ 
in Fig. 7. 

The ropes to be balanced here are the hoisting rope from 
the car to the overhead sheave and the counterweight rope , 
from the counterweight to the overhead sheave, denoted, in 1 
Fig. 7, by //and C. respectively. The former can be bal- 
anced by a chain j*/' of equal weight and an increase of the 1 
counterweight by the same amount, while the rope C can , 
be balanced simply by a chain C. Of course, two chains I 

would be actually used, each weighing — ^ — . 

14. All counterbalancing means an addition to the mov*-l 
ing masses of the elevator, which, again, means an increase'! 
in the power required to set these masses in motion, as well ' 
as greater braking power to slop them. These considera- i 
tions make it desirable in certain elevator types to foregtt I 
the advantages of overbalancing. 

§37 ELEVATORS. 11 


15. The counterweights consist generally of cast- 
iron blocks carried in a frame or on a rod or rods and 
guided by suitable guideways. The blocks are made long 
and wide, but thin, in order that they may take up but 
little room. In hydraulic elevators the counterweights are 
sometimes attached to the piston rods, either inside or out- 
side of the hydraulic cylinder. 

The counterweight guides are made of angle or T iron, 
seldom of wood. 


16. Kinds of Controlling I>evlees. — The controlling 
devices of all elevators consist of a power control, that is, 
means for shutting off, turning on, and regulating the 
power at will to start and stop the car, and some kind of a 
brake, the function of which is to effect a prompt but 
gradual, and therefore safe, stoppage of the car. 

The power control and brake are essential parts of the 
motor in each case and are, therefore, located near the 
same; they are naturally different for different kinds of 
motive power, and will be described at length in connection 
with the various types of elevators. There is, however, with 
respect to the controlling devices a certain feature common 
to all. 

Since most elevators are operated from the movable car, 
some flexible connection must exist between the same and 
the controlling devices on the motor. The means for making 
this connection, which we will call operating: devices, are 
either mechanical or electrical. The latter is used to any 
extent only with a certain kind of electrical elevators, while 
the mechanical connection is employed on all types in the 
shape of a sliipper rope running all the way from the top 
to the bottom of the hoist way and either simply passes 
through the car or is connected with some apparatus inside 
the car. 





IT. Din^rent Opentlnic Dericvs. — The amplest 
arruigem^Dt i$ a pEain endless n^ie bang over one or more 
, iiiiers and attached to the alilpper ataesTe 
•T a lever, so that a poll either up or dorn 
'>n the shipper rc^ mores the sheave or 
Ie\-er. vhich is located oa or near the 
motor and is mechanically connected to 
the c»ntr>>lling devicesof the same. This 
simple arrangement, which is shown dia- 
grammaticallr in Fig. 9, is open to sev- 
eral objections, one of which makes its use 
undesirable in connection with all motors 
requiring a delicate adjustment of the 
controlling device, such as hydraulic 
motors controlled by a pilot valve and 
electric motors, inasmuch as the operator 
has no means of telling the exact posi- 
tion of the controlling device. An- 
other objection is that there is neces- 
sarily a great deal of sliding of the 
rope through the hand of the operator^ 
which is not only inconvenient, but may 
prove dangerous from broken strands. 
The operator should provide himself 
use a piece of rubber hose split 

■.h a leather jjli 

C'lme the objections to the simple 
lices have been invented and put 
vo the ..bject of changing the 
r<jif im>' the motion of a lever 
■ ]•'• are shuwii a number of these 
1. jianii'tilariy in connection with 
the arr;in';enient shown in Fig. 10, 
It-vor ,( in the ear, the long arm 
ny: ti) the right or left by the 
e short arms is connected a rope R 
kr carried by another three-armed 

8 37 



lever B pivoted at the bottom of the hoistway. From 

the idlers on lever B the ropes R, R pass up again and 

over idlers fixed at the top of 

the hoistway, as shown. On 

the ends of the ropes are 

counterweights whieh 

equal, and each is somewhat 

heavier than the equivalent 

force necessary to move the 

controlling device of 

motor, which is mechanically 

connected to the third arm 

of the lever H. As will be 

easily understood, the wholt 
arrangement is in equilibrium 
in any position of the lever .^, 
but the equilibrium is dis- 
turbed as soon as a pull is 
exerted on it in either direc- 
tion, in consequence of which 
the second lever B will follow 
the motions of A and stay 
in a position corresponding 
to that of A. The top idlers 
are shown in the diagram on 
separate shafts or studs; in 
reality they are placed side 
by side and the downward- 
rope passed through the counterweight nearest to it, as 
shown in Fig. 10 (a). The weight Is thus guided on the 
rope. To prevent abrasion of the r<)pe, a rubber ring is 
inserted in the hole through the weight. 

10, Another arrangement is shown in Fig. 11. The 
shipper rope is led fmni a fixed point a at the lop of the 
hoistway over two idlers /' and c mounted on a lever I. 
pivoted to the car and handy to the <iperator. From the 
idlers b and c the n>[)e is carried farther down, around 




tilt- shipper sheave S, and thence back upwards over 
two more idlers c' and d\ also attached to the lever L, and 
is finally fastened at the top at d. While the car moves 
up and down, the shipper sheave 5 
is stationary unless the lever L is 
moved. By moving L upwards, the 
part d c S oi the rope is doubled up 
more, while the part i' c' S is 
straightened out an equal amount, 
causing the sheave J> to take a 
position depending on that of the 
lever Z, in which position it remains 
- until the lever is moved again. In 
an actual machine the idlers are 
mounted on studs, b and c' on one 
stud and b' and c on another stud, 
which are carried on a lever out- 
side the car; the pivot of the lever 
is carried through into the interior 
of the car, where it carries the 
handle L' [see Fig. 11 {<?)]. A 
hand wheel may be substituted for 
the handle L'. 

20, The same idea that under- 
lies the arrangement of Fig. 11 is 
embodied in Fig. 13. Here the 
two branches of the rope are 
deflected so as to pass over two 
idlers /, i' on the same stud and 

are attached to a lever pivoted to the car; the other 

idk-rs (7, /', c, and (/are fixed to the car. 

31. The devices shown in Figs. 11 and 12 necessitate 

dlers to be c;irried on the car, where they must, owing to 

he limited space available, be necessarily small. This 

detrimental fi the ropi'. especially since it is bent in 

losite dircctiniis in quick succession. These objections 

§37 ELEVATORS. 15 

do not prevail in the arrangement shown in Fig. 10, where 
the idlers may be ample in diameter and the ropes are 
bent in one direction only. 

22, An improvement on Fig. 12 is the operating device 
shown in Fig. 13, in which the ends of the ropes are 
attached to the car instead of to moving weights ; a single 

Fio.ia. Fig. la. 

Stationary weight a attached by a rope to a cross-bar, or 
frame, b carrying the upper idler is substituted for the 
moving weights. 

23. This arrangement has been still further improved 
upon in the manner shown in Fig. 1-1. The ends of the 



I 37 

ropes that were attached to the car in Fig. 13 are here alwi 
attached to the lever arms, and the two ropes leading from 
the lever of the two idlers are crossed. It can easily be 
seen that by this means the motion of the lever gives 
twice as much motion to the sheave as in the arrange- 
ments shown in Pigs. 10 and 13. 


24. The iiporatiiip; device last described is known as the 
Oti« U'vei*. or o|ioiittlnw devloc, and is now used almost 
exclusivfly nn the liydraidJc ek-vators of the Otis Elevati>r 
(.■iinipatiy. By substituting a hand wheel or crank for the 
levL-r in I-'i^. i:! and atUiching the lower idlers to the ship- 
jjiT s;ht-ave, a nmdification shown in Vi^. 15 is obtained that 
is found uri a iiooil many cK'valuis of tlie Otis make and 
is <alkd a iuuKl-wlicel o|>ci-n(lnur <l«-vl«-.-. By elevator 



1 3! 

5 [he operating devices are often called eontroUers 
and arc spoken of as lever cootrollei's, hand-wheel coq- 
troUent, etc, Since the term controller is also given to the 
combination of switches and resistances constituting the 
controlling device proper in electric elevators, the practice 
just mentioned is not followed here in order to prevent 

•iJS. A common arrangement of a hand-wheel operating 
device is shown in Fig. lli. The sheaves A, A are sta- 
tionary, but the sheaves B, B'. being loosely mounted on 
guide rods, can be shifted by means of the hand wheel D 
unci chnin E. The chain runs over the wheels C, C. After 
the explanations of the operation of the different ojierating 
devices thai have been previously given, the operation 
this one will be easily understood. 


"8 'Jll 


HC We can divide the safety ilerlccs used on elevators 
into two dtMinct classes: thi»se that control the power sup- 
ply, which we shall call motor snfetles, and those that 
iimtrv^l the car indeivndently of the pouer supply, which 
Wr Khali call vur <wft>tU-«. The former must necessarily be 
tTT.ttovl in v>>nn<x'tit.^i with the \'anv)us styles of motors used: 
^ihe latter alK>w i>f. and their importance warrants, a treat- 
mi by tlwiu:iel\TS, whicb will be given in its proper place. 


e varioBJ^I 


■ shall class all those v 

^tfttNTVN'VQt Atvid<-nts from causes o 

\t^ati>r 1^ any of its ports, and to 

I of thv traxYting public and the efh- 

SiK'ii appbaaces arc atito- 

^ uri lMitvh«a)>v sig^uK. iodkaiors, etc. 

§37 ELEVATORS. 19 



28. When an elevator is to be used but little, and espe- 
cially if speed of the car. is not essential, it does not pay to 
use steam or other motive power; hand-power elevators 
are then useful. With few exceptions they are installed for 
freight service only. 

Figs. 17, 18, 19, and 20 show several types of hand-power 
elevators. Those shown in Figs. 18 and 19 are made by 
Morse, Williams & Co., of Philadelphia, Pennsylvania, and 
those shown in Figs. 17 and 20 by the A. B. See Manufactur- 
ing Company, of Brooklyn, New York. 

29. Motor. — The motor of a hand-power elevator is rep- 
resented either by a shaft actuated through a rope sheave 
and endless rope, the latter being pulled in either direction 
by hand, and examples of which are shown in Figs. 17, 18, 
and 19, or it is represented by a crank driving a windlass, 
as shown in Fig. 20. 

30. Transmitting: Devices. — The transviitting devices 
consist of spur gearing in connection with either a drum for 
a rope or chain, as in Figs. 17, 19, and 20, or a friction 
sheave, as in Fig. 18. 

31. Operating Devices. — The operating device is a 
manila rope, preferably a four-strand and ** stevedore" 
rope ; the hoisting and counterweight ropes are generally wire 
ropes. In the sidewalk elevator shown in Fig. 20, chains 
take the place of the rope. 

32. Cars. — The cars in Figs. 19 and 20 are different 
from the ordinary cars, inasmuch as they are supported on 
all four corners. 

Small hand-power elevators are used largely for carrying 
small loads in dwellings, restaurants, libraries, etc., and are 
called dumbwaiters. The cars of these then take the shape 
of a bpx with or without shelves. 



3;*. GuliU'w and CimnterwelBht. — In the elevator 
shiiwn in Fig. 19 guiJis are provided on one side only. 
The counterweight in Fig. It is hung from a separate drum; 

in Fig. lit it is hung from one of the hoisting drums; 
Fig. IH it is attached to the olher end of the hoisting cable^ 
and in Fig. VO the cminterwcight is dispensed with entirely^ 

34, Con ti-ol ling Devices. — The coulrollhii^ device in 
Pigs. 17, 18, and 13 consists only of a brake li, which is applied 
ly aweight (I'and is loosened by the operator by means of 

hand rope. In the windlass, or winch, type of elevator, 

W. J-. /-.-/J 


shown in Fig, 'iO, the brakf is actuated, both in applyir 
and loosening it, by operating the lever /. by hand. Sinct 

Fig. m. 

the brake is not applied automatically, a pawl Pis thrown I 
in mesh with the glaring when the elevator is at rest. 
35. Motor Safotk's. ^Hand-power elevators have i 

motor safe lies. 



36. The mechanisms of hand-power elevators are so 
simple that any one can operate them without difficulty; 
nevertheless, no less care should be exercised in handling 
them than power-driven elevators. Carelessness and neglect 
will prove just as dangerous with hand-power elevators as 
with any other type. 

37. Hand-power elevators cannot be operated from the 
car, but are operated from any floor; a person riding on the 
same has no control over its movements and takes consider- 
able risk. In operating, the operator lifts the brake and 
pulls the hand rope. In the design shown in Fig. 17, he 
must hold on to the brake rope, or check-line, as it is 
called, as long as the car is to move. This necessity is 
avoided by the arrangement shown in Figs. 18 and 19, the 
check-line passing over a number of small friction pulleys 
that give enough friction to the rope to hold the brake on 
or off after the operator has moved it by either an upward or 
downward movementof the hand. This device is a peculiarity 
of the hand-power elevators built by Morse, Williams & Co. 

38. As the first and foremost rule it must be remem- 
bered that an elevator is built for a certain maximum load 
and that this load should never be exceeded. 

39. All elevators should he started and stopped gradu- 
ally. It takes more power to run an elevator up to a 
required speed than to maintain that speed thereafter; this 
additional starting power is the greater the shorter the time 
within which the necessary speed is attained, and the 
greater is also the stress in all parts of the machinery. 
Likewise, it takes considerable power to stop a moving 
elevator, which power is supplied by the braking device, 
and which is required to be the greater the quicker the J 
elevator is stopped. Thus, if an elevator is stopped too 1 
quickly, enough stress may be put on the braking device to j 
destroy it, causing accident. In hand-power elevators there ' 
is hardly any danger from quick starting, but there is from J 
a sudden application of the brake, especially if the elevator | 


§ 37 ELEVATORS. 25 

is underbalanced and, as is often done, allowed to attain 
considerable speed in descending. 

40. The drums, sheaves, and gears should be frequently 
inspected as to their fastenings to the shaft. 

41. The brake needs particular attention, as the safety 
of the elevator depends on it. 

42. If any car safety is provided, as there should be, 
the same should be examined frequently and carefully until 
the operator is satisfied that it is in good working condition ; 
its parts should be kept well oiled and should be kept clean, to 
avoid their sticking and refusing to act in case of an emer- 


43. All that is said in Arts. 44 to 61 applies to all 
elevators, inasmuch as in all of them wire rope is used more 
or less and all have guides. 

44. The wire ropes used in elevator work are made with 
hemp centers, to make them more pliable and thus more 
durable, on account of the short bends over comparatively 
small pulleys, or sheaves. Galvanized rope should not be 
used; the thin coating of zinc soon wears off, leaving the 
wires exposed to rapid deterioration by corrosion. 

45. The wire ropes should be examined often and care- 
fully; hoisting cables should be condemned as dangerous 
when the wires (not the strands) commence cracking. 
Wire ropes used for hoisting should under no circumstances 
be spliced. 

46. Wire rope must be handled much more carefully 
than hemp rope, inasmuch as it is liable to kink and twist, 
which must be avoided on account of the harmful effect. 
Wire rope is best mounted on a reel that can be placed on a 
spindle to pay out the rope. If received from the supply 
house without a reel, the rope should be paid out by rolling 
the coil over the ground like a wheel. Wire rope should be 
lubricated like other moving machinery parts to preserve it. 


To prevent rusting, raw linseed oil shnuM be used and 
applied with a piece of sheepskin. The J. A. Roebling Sons 
Co, recommend to mix the linseed oil with the equal parts of 
Spanish brown or lampblack. The Otis Elevator Company 
recommend a mixture of " parts of linseed oil and 3 parts of 
tar oil. Another good preserving lubricant is made by 
ht-ating and mixing well cylinder oil, graphite, tallow, and 
vegetable tar. When the rtipes, or rallies, as they are called 
frequently in elevator work, have once become well soaked, 
they need oiling only about cvtry third or fourth month. 
They should not be allowed to become dirty and gummy. 

47. In replacing worn ropes, particular attention must 
be given to the fastenings. In all cases where the ropes aie 
replaced for the first time, it is best to carefully reproduce 
the joint as it was originally made by the makers or instal- 
lators. An engineer taking charge of an elevator plant will, 
however, sometimes find rope fastenings of an inferior kind 
made by his predecessor. It may, therefore, be in order to call 
attention to the principal methods used by manufacturers. 

48. The sbatrkle used by the Otis Elevator Company 
is shown in Fig. 21. It consists of a split rod, the two 

legs A, A of which are bulged out and provided 
with noses at the ends. A collar B straddles 
the legs and eventually abuts against the noses. 
The rope is brought through the collar, bent 
over a thimble C, and passed back again through 
the collar, after which the free end is fastened 
by wrapping with wire. The wrapped end of 
the rope should be at least 8 inches long. The 
inside surfaces of the legs A and the outside 
surface of the thimble are concave to conform 
with the rope. Instead of the wire wrapping, 
clamps are sometimes used; the wrapping is to 
Flo SI be preferred, however. 

49. Another fastening is shown in Fig. -2-2. The rope is 
passed through a socket A forming part of the shackle; 
then it is untwisted for a short distance and the individual 




wires bent double. The socket is then filled with molten 
lead, or, better, with Babbitt metal, which should be of the 
best quality. The sockets should 
be warmed before the metal is 
poured to prevent chilling. 

60. In fastening the rope to the 
drum, it must be observed that at 
the lowest position of the car the 
rope must still encircle the drum 
several times to reduce the stress 
at the point of fastening. 

51. The guides should not be 
allowed to become gummy and 
should, therefore, be cleaned from 
time to time — about twice a 
month — and freshly lubricated. Gummy guides cause 
the car to alternately stick and free itself, making its 
motion jerky; and a bad case of sticking may cause the 
car to drop a distance great enough to break the cable and 
thus cause serious accident. In cleaning guides, a judicious 
occasional use of kerosene oil is recommended. For a lubri- 
cant on steel guides good cylinder oil is used ; some use a 
comp)osition that is seven-eighths cylinder oil and one-eighth 
plumbago, well mixed. Wooden guides are greased with 
No. 3 Albany grease or lard oil; a mixture of tar oil and 
wax is also recommended by some. 


Fig. 22. 



52. The term belt elevator is applied to that class of 
elevators that are driven directly by belts from line shaft- 
ing, which shafting, in turn, may be driven by any prime 
mover and may be used for driving other machinery at the 
same time. Belt elevators are used for freight service 
principally, seldom for passenger service. 



53. The shaft from wiiich the powt-r is taken rcvidvcj 

in ihf siime direction independently of the 
ih.- -■U-vaior — that is, uncontrolled Iw Uie 

§ 37 ELEVATORS. 29 

operator. The power is transmitted from this shaft to the 
elevator machine either direct, if the shaft is conveniently 
located, or by a countershaft. In either case, the shaft or 
countershaft carries a wide pulley that drives two belts, an 
open one a, Fig. 23, and a crossed one b. The elevator 
machine c is preferably placed on the ceiling, as shown, to 
save floor space, but it may be put on the floor as well. 
In many cases it will be possible to place it directly over the 
hoistway and thus save the expense of overhead sheaves. 


54. Following up the various parts again in the order 
named in Art. 2, they present themselves as follows: 

The motor of a belt elevator is simply a shaft carrying 
two loose pulleys and one tight pulley ; it is designated by 
M in the various illustrations following hereafter. 

The transmitting devices consist of either worm-gearing 
or spur gearing connecting the shaft M with the drum, 
worm -gearing being by far the more common arrangement. 

When counter balancings worm-geared belt elevators are 
generally overbalanced ; spur-geared ones are not. The rea- 
son for this is that worm-gearing works much smoother 
than spur gearing; it starts and stops gradually, offering 
much more resistance during the period of getting up speed, 
and acts as a kind of brake by itself in bringing the elevator 
to rest. The addition to the moving masses due to over- 
balancing, therefore, greatly increases the jerkiness of 
motion in spur-geared machines, while it has little influence 
that way in worm-geared ones. 

The controlling devices consist of a pair of belt shifters, 
constituting the power control, and a brake, both being 
operated simultaneously by a shipper rope. 


56. In a belt elevator the controlling devices must be 
constructed in such a manner that the following require- 
ments are fulfilled: 


8 37 

§ 37 ELEVATORS. 31 

(a) When the shipper sheave is in the central position, 
both belts must be on their respective loose pulleys and the 
brake must be on, 

(d) When the shipper sheave occupies the extreme right- 
or left-hand position, one belt must be on the tight pulley, 
while the other must be on its loose pulley, and the brake 
must be off. 

(c) In their respective driving or non-driving positions, 
the belt shifters must be locked in place, so that they can- 
not be accidentally shifted. 

(d) It must not be possible to throw the shipper sheave 
over too far. 

(e) The central position of the shipper sheave must be 
distinctly defined, so as to give the operator warning against 
overthrowing the sheave from the one extreme position to 
the other. It is evident that this danger always exists. 

56. The requirements stated in Art. 55 are met in vari- 
ous ways in practice. Fig. 24 shows in a diagrammatical 
way a typical arrangement for this purpose. The figure 
does not represent an actual machine, but was prepared to 
show the various elements of a belt elevator, separately 
explaining their functions. The shipper sheave 5 has two 
cam grooves into which enter corresponding pins /, p' on 
the ends of the belt shifters ii, £'. 

The cam groove, it will be noticed, has one concentric 
middle portion and two eccentric side portions. 

When the sheave is in a central position, as shown, both 
belts are on their respective loose pulleys. A pull down- 
wards on the shipper rope R swings the shipper sheave 
around to the left; the pin p of the left-hand belt shifter 
enters the left-hand eccentric portion of the cam groove and 
is thus forced to the right, while the other pin/' travels in 
the concentric portion of the groove and thus remains 
stationary. The open belt is thus shifted on to the tight 
pulley /* while the crossed belt remains on its loose pulley; 
the elevator car then ascends. On pulling upwards on the 
rope Rj the reverse takes place and the elevator car descends. 

3-> ELEVATORS. § 37 

On the hub '•! the shipper sheave a V-shaped cam groove 
is formed, into which enters a pin g in the middle of a lever 
that carries <^«n the one end a brake shoe B and on the other 
a weight \\\ which latter is so connected to it by means of a 
system of links that it tends to keep the brake on the tight 
pulley : a swing of the sheave either to the right or left lifts 
off the brake. Thus requirements (tf) and (^), Art. 55, 
are fulfilled. Requirement <r) is met by the shape of the cam 
groove, and n« a «:»nly are the shifters locked to the sheave in 
whatever posit i« in the same may be in, but also while one 
shifter is being moved the other is held positively and 
immovably in place by virtue of the concentric position of 
the cam groove. 

Requirement (d) is met by the proper length of the 
groove, and requirement («) by the sharp comer of the 
V groove, which will make itself distinctly felt to the touch 
of the op)erator. 

57. As already said, the simple shipper rope is used for 
an operating device^ special devices, such as described in 
Arts. 18 to 25, being uncalled for, owing to the com(>ara- 
tively slow speed of belt elevators and to the fact that the 
car begins to move only after the belt has been shipped a 
considerable distance, so that it requires but little skill to 
complete the shift during the accelerating p)eriod of the car. 


58. I.iniit stoi>s on JShlpiH*r Rope. — In all elevators 

that are run by m«»live power the danger exists, if no pro- 
vision he made a^^ainst it, that, through the operator failing 
to arrest the ear on time, the car or cotinterweight may be 
hoi^trti a;;ain^t the overhead work, causing damage and 
a( < ident. Such danj^er d<)es not exist in hand-power eleva- 
tors with their slow speed, the resistance immediately being 
f<-lt by th<.- hand when the car strikes an obstruction. It is, 
thcretorr, one of the provisos in every power-elevator design 
that the j)«)wer be shut off and the car be automatically 
arrested at the limit of its travel up or down. 

8 37 



The means adopted for this purpose are called llmltstops, 
and are of various designs. In all cases where a shipper 
rope passes straight through the car, knobs or buttons are 
clamped on the same, against which the car strikes when 
neariog its upper or lower limit of travel, thus operating 
the shipper sheave automatically. This means, of course, 
operates only as long as the shipper rope is intact. As it 
may easily occur that the shipper-rope connection is broken 
or the rope is otherwise ineffective, limit stops are also always 
provided on the motor itself. 

59. I.liiilt Stope on Motors. — For drum elevators the 
most common arrangement is that shown in Fig. 25. Let^ 

be a continuation of the drum shaft shown broken off in 
Fig 24. A screw thread is cut on this shaft and a gear- 
wheel n, the hub of which forms a nut, is placed on the 
threaded portion of the shaft; this gear-wheel meshes with 
another similar wheel «' bolted to the shipper sheave. It is 
evident that when the sheave is stationary and the drum 
rotates, the gear-wheel ii will be prevented from revolving 
with the drum shaft, but will travel on the same in an axial 
direction either towards or from the drum, according to the 


sieasc of rotation of the latter. The hub of the wheel a has 
cla<rs on either side, as shovn, corresponding to similar claws 
formed on two other nuts m and m' that are clamped by jam 
outs/ and y". or in some other manner, securely to the drum 
shaft A. Now, it will be easily understood that when 
the wheel » travels either way, it will evcnlually be engaged 
by either one of the reviMving nuts "» or w' and be swung 
around, carrying with il the shipper sheave, with the effect 
of cutting off the power and applying the brake. The 
nuts w and w' can easily be adjusted to any position on 
the threaded portion of the drum shaft, and can thus be 
made to act when the car reaches the upper or lower limit 
in the hoistway. 


00. Should the elevator car be obstructed in its descent 
by gummy gu-des or for any other reason and the motor 
continue to pay out the cable, the car would, if released 
suddenly, drop and most likely break the cable, causing 
damage; or should the car not drop, but be resting, for 
instance, on the bottom of the hoistway, the slack cable 
might still cause damage by getting into revolving parts of 
the machine. In any case, if the hoisting cable becomes 
stack, it will quickly be riding over itself on the drum or 
otherwise get entangk-d and must be straightened out again, 
which entails much labor and annoyance. A frequent occur- 
rence is a slack cable produced by a careless handling of the 
shipper rope. It can often be noticed that when an operator 
1 going up has missed his landing, he hastily reverses the 
Machine to make his error good ; the result is that the hoist* 
Wg cable becomes slack. Now, most car safeties are so 
arranged that they will bind the car to the guides on the 
cables becoming slack. In his perplexity at the sudden 
ttoppagcof the car. the operator is likely to forget to shift 
*l>e shipper rope so as to slop the machine, and the latter 
jgoes on paying out mpc. Provision is made against such an 
emergency by contrivances called ^lack-caMe ^fvties. 

§ 37 ELEVATORS. 35 

Fig. 25 shows the principle underlying such an arrange- 
ment: An idler i travels axially on its shaft s with the 
hoisting rope along the drum. The shaft s is supported 
on levers /, f pivoted in a convenient manner. A cord c 
leads from the arm f of the lever /' over sheaves to a bell- 
orank b, one arm of which is weighted, while the other 
engages a clutch C, As long as the hoisting rope //is taut, 
the idler / is pushed outwards against the weight on the bell* 
orank b\ but should the hoisting rope become slack, the 
^w^eight on the bell-crank b will cause the clutch C to engage 
^vrith a gear-wheel g mounted loosely on the drum shaft, and 
vrill cause the same to revolve with the drum shaft. The 
gear-wheel^ meshes with another gear-wheel // fastened to 
the shipper sheave, so that the latter will be swung around 
when the hoisting cable becomes slack. 

61. The principles illustrated by Figs. 24 and 25 are 
found embodied in all belt elevators in various ways. 


6C Fig. 26 is a plan, elevation, and side view of a worm- 
geared belt-elevator machine built by The Whittier Machine 
Company, Boston, Massachusetts, and designed to be placed 
on the floor. While there is no particular difficulty about 
understanding the operation of the machine, a few explana- 
tions will nevertheless be in order. The machine has two 
worms, one left-handed and one right-handed, actuating two 
worm-wheels that mesh together. This combination pre- 
vents the end thrust, which is unavoidable in single-worm 
machines and saves the power necessary to overcome the 
frictional resistance due to it. There is, consequently, also 
no wear to the end of the shaft, and no step bearing is 
required, as in single-worm machines. 

With regard to the controlling devices, it will be noticed 
that the belt-shifter cam groove is continuous. Special 
provision is, therefore, made against throwing the sheave 
over too far by fastening a stop-plate T to the frame, and 








- - - L • .'« 




§ 37 ELEVATORS. 3 

t>y stops /, / formed on the hub of the shipper sheave, as 
shown in detail in Fig. 2G (a). 

'^l^lie central non-driving position of the controlling device 
1^ rnade perceptible to the hand of the operator by nicking 
the brake cam, as shown in dotted lines at a in Fig. 20. 

The limit stops are arranged practically in the same man. 
^^r as in the typical drawing given in Fig. 25. The slack- 
caljl^ safety is, however, radically different, inasmuch as the 
^^TiHion of the hoisting rope is not made use of; but, 
instead, the weight of one or more turns of rope hanging 
^'■<^>m the drum underneath in case the cable should become 
slacrl<. For this purpose a rod r is placed across and under- 
^^^th the drum, which rod is attached to the end of a 
'^ei^ht-actuated lever that is tripped and closes the clutch C 
^'^hen there is any weight resting on the rod r. Both kinds 
^** Hlack-cable safeties are extensively used. 

^>3. Fig. 27 shows a worm-geared elevator built by Morse, 

^ i 1 liams & Co. , Philadelphia, Pennsylvania. In this machine 

^^ various requirements are fulfilled by slightly different 

^^^i^ns than have so far been -shown, although the principles 

**^^^ the same. The difference lies in the manner in which the 

. ^ J^ ti shifters are moved. Instead of the shipper sheave carry- 

^%C the cam, the belt-shifter bars n and /? have slotted cam 

*~*^^^es it' and d' attached to them, and the sheave carries two 

^^'titons, or projections, / and />'. It is easily seen that the 

^^^?ct is the same as when the shipper sheave carries the 

'■^^^, with one advantage. As will be shown presently, it 

" ^'V'^es a good deal of complication in the way of gearing to 

^^t the shipper sheave loosely on the drum shaft instead of 

*^^^cing it on a separate stud, or shaft, in line with the 

^^ifter bars, as was done in the machines shown in Figs. 24 

^nd 26. 

As this, however, throws the center of the shipper sheave 
^Ut of line with the shifter bars, the distance between must 
be bridged over. When iisinj^ a cam on tin* sheave, this is 
done ordinarily by interposinjj: doublc-arin levers /and /', as 
shown in Fig. 28, so that one advantage is gained at the 

//. 5". V.^J4 

38 ELEVATORS. g 87 

sacrifice of another in that case. By arraagiag: the parts 
as in Pig. 27, the necessity of the double-armed levers is 
avoided, making the machine so much simpler. Both types 
are in extensive use, however. 

RL-vertinK to Fig. :JT, it will he seen that in turning the 
shL-a\x 111 the rijilit. for instance, the right-hand belt will be 
shifu-il (in to the tight pulley A by virtue of the button p' 
enierin;.; liie fain griMive on the corresponding shifter-bar 
ram i)iece ri'. Tlie left-hand button /*, however, will leave 
(Is larn /'' entirely, and if ni> juxivision were made against it, 
the left-hand shifter wuulil be unprotected, that is, liable to 
111- Muiu-d ariid.-nially. To avoid this, that is. to lock the 
slaiionary shifter bar in place while the other is being 
niuvL-d (si'<: reiinirenieiit {<}, Art. S3}, a circular groove ^ 

§37 ELEVATORS. 39 

is formed in the shipper sheave 5, which fits over pins h 
and k inserted in the shifter cam pieces a! and V . 

The central, or non-driving, position, as well as the 
extreme right and left positions, are strongly defined to the 
operator by the shape of the brake cam, which has a wide, 
flat surface for the neutral position and two smaller flat 
surfaces for the end positions, with the effect that when 
either of the corners c or c' of this cam passes through a 
position vertically below the center of rotation, the sheave 
will come to a quick and sudden stop. 

64. It was mentioned in Art. 63 that by placing the 
shipper sheave on the drum shaft a simpler arrangement for 
the limit stops can be had. The usual arrangement is 
clearly shown in Figs. 27 and 28. The shipper sheave is 
provided with a yoke j, which takes the place of the hub. 
The yoke has formed on it a feather or rib /", upon which 
slides the traveling nut ;/ that eventually engages with the 
fixed nuts m and m' in the manner already described. It is 
thus seen that the gearing shown in Figs. 24 and 26 is dis- 
pensed with. The yoke arrangement is in most extensive 
use and is found on almost every drum-elevator machine. 


65. The operation of belt elevators requires but little 
skill, the speed being comparatively slow; nevertheless, a 
certain amount of practice is required to *'make the land- 
ings *' exactly. 

66. The operator should never rely on the limit stops 
to make a top or bottom landing, but should always operate 
the rope as at any intermediate floor. The limit stops are 
provided for an emergency and not for general use. They 
should be tried, however, once or twice every day, to see if 
they are operative and correctly set. The operator is to 
be cautioned against sudden reversals of the controlling 

40 ELEVATORS. §37 

67. The brake needs adjustinj]^ from time to time. The 
necessity for this manifests itself by the car *' settling*' at 
the landings. A good deal of judgment is necessary in 
adjusting the brake ; it should not grip too soon nor too late. 

68. The belts should be kept under inspection and not 
allowed to become too slack. As new belts stretch consid- 
erably for a long period of time, they need closer attention 
than old ones. 

69. Belt-elevator machines should be so installed, if pos- 
sible, that the belts are not subjected to the influence of 
water, steam, or other moisture. In many cases, as in 
some factories, breweries, etc., this cannot always be done; 
it is then advisable to dress leather belts with a leather 
waterproofing compound, various brands of which are in the 
market, or to use rubber belts. Only first-class material 
should be used for elevator belts, especially if they are to be 
run in moist or damp places. Be careful to prevent oil from 
dripping on either leather or rubber belts, as the life of the 
same is greatly impaired thereby. Leather belting does not 
remain safe for any length of time in a temperature above 
110° F. 

70. In ucnerai, it is to be said that the elevator machine 
needs as niiuh care as any other machine on the premises. 
It is loo often considered of secondary importance and is 
neglected by I lie eiij^ineer in charge, especially as it is placed 
on ihr cciliiv.^ and more out of reach than other machinery. 
The hcariiiLis should be kcj^t well oiled and the gearing 
sh-'iij-l ])(• krpi ("Iran. Willi regard to worm-gearing in par- 
li'ular, i; may be well to nieiuion ihat in the better class 
of inai inii< > ii i^ rnrlosi'd in a casing, and the worm runs 
< ill «»ii. This oil bath should be kept full and 
<»(<a<i' >:ially icnewrd to remove dirt and grit that may have 
a<( innnlaicil. Willi lu-w elevators this should be done 
111' 'If' frecjiirntly than with the old ones that have been **run 
in": uiih these fre>h oil should be put in every two or 
three nit'iuhs. 

§ 37 ELEVATORS. 41 

?!• Worm-gearing when new should, if possible, be 
less heavily loaded than when run in. A judicious observ- 
ance of this rule is sure to prolong the life of the gearing 
considerably. Although conscientious manufacturers run 
in their worm-gearing before shipment, they can naturally 
do so only to a limited extent. It is said that the best oil 
to use on the worm bath is castor oil. The fact, however, 
that castor oil thickens when it becomes heated and that 
more or less heat is developed on worm-gearing, makes it 
desirable to use a mixture of 2 parts of castor oil and 1 part 
of the very best cylinder oil. Upon getting warm the cylin- 
der oil runs freely, thus compensating for the property of 
castor oil mentioned. 

73. Particular attention is to be paid to the lubrication 
of the thrust, or step, bearings of the worm, which should 
be renewed as soon as they show signs of cutting, since they 
will rapidly go from bad to worse. The step is generally 
made adjustable. The adjustment should be such that there 
is a little end play for the worm-shaft, say a scant thirty- 
second of an inch. This end play gives the oil a chance to 
enter between the bearing surfaces at every reversal of the 

If the steps are screwed up too tight, they will run hot at 
once and soon seize. The same as the \vorm and wheel, the 
step bearing requires to be run until a full uniform bearing 
surface is attained by a mutual adjustment through wear of 
the journal and its step. This mutual adjustment can be 
greatly facilitated by placing a leather washer behind the 

73. Overhead sheave boxes must not be neglected. 
They should be kept lubricated with heavy grease in sum- 
mer, with an addition of cylinder oil in winter. 

74. Belt elevators should ordinarily not be run at a 
greater car speed than (U) feet per minute. The pulley 
speed should not exceed 400 revolutions per minute. 

42 ELEVATORS. § 37 



75. Motors. — Owing to the necessity of prompt start- 
ing, stopping, and reversing, the engines used for steam 
elevators are, without exception, duplex engines, generally 
of the vertical type. The cylinders are placed either on top 
or bottom, according to the kind of gearing used. Ordinary 
slide valves are used by some manufacturers, piston valves 
by others. 

76. Transmitting Devices. — Practically all steam ele- 
vators are drum elevators. According to the kind of gear- 
ing used to connect the engine and drum, we can divide the 
elevator machines in general use into the following classes: 

Direct-eeared elevators with ■] ^ «* .*** 

( worm-gearmg. 

Belt-eeared elevators with "I 

^ ( worm-gearmg. 

An example of an elevator of each class is given in 
Figs. 29, 31, 32, 33, and 34:. The illustrations given do not 
by any means represent all the various designs of steam ele- 
vators, but have been chosen simply to illustrate the four 
types in most general use. 

77. Counterbalancing:. — Steam elevators are usually 
overbalanced when made with w^orm-gearing, but are not 
overbalanced when made with spur gears, for the same 
reason as belt elevators. 

The enji^ine thus furnishes full power only on the up trip 
of the car, and as the unbalanced portion of the car weight 
is j^enerally considerable in steam elevators for the sake of 
safety, the engine must be of comparatively large capacity. 
To do away with the waste of energy in raising the unbal- 
anced dead load of the car, and at the same time to avoid 
the use of the large moving masses of counterweights, 
recourse has been had ore asionally to the expedient of con- 
necting two cars with one hoisting drum, the ropes being so 

§ 37 ELEVATORS. 43 

attached to it that when one car ascends the other descends, 
the motor furnishing power when the load on the ascending 
car is equal to or greater than that on the descending one. 
It is evident that the pressure on the bearings of the hoist- 
ing drum is equal to the weight of both cars plus their loads, 
and the stress in the hoisting ropes is equal to the weight of 
one car with its load. By connecting the two cars by a 
separate rope running over overhead sheaves, the bearings 
of the drum and the hoisting ropes are relieved of the car 

The obvious advantages of this double-car method of 
counterbalancing are, of course, gained at the disadvantage 
that both cars must move simultaneously. 

78. ContPolUngr Devices. — The controlling devices of a 
steam elevator consist of a steam-reversing valve and brake 
operated by a shipper rope, which is either a simple shipper 
rope or is in connection with some lever or wheel-operating 

79. The steam valves used in the machine represented 
in Fig. 29, which is an Otis spur-grearecl steam elevator, 
are piston slide valves operated, as in most slide-valve 
engines, by eccentrics on the main shaft. 

80. The reversing valve, which is shown in three posi- 
tions in Fig. 30, reverses the motion of the engine by chan- 
ging the piston valve of each engine from a direct to an 
indirect valve, and vice versa. Referring to Fig. 30 (a), the 
reversing valve a is shown in the position it occupies when 
hoisting. The valve is surrounded by live steam, which is 
also admitted to the cavity d. The live steam now flows 
through the ports r, c' into the passages e and e' leading to 
the ends of the piston valve, which now operates as a direct 
valve, taking steam at the ends and exhausting at the center. 
The exhaust from the piston valve passes through the pas- 
sage ^and ports ^, o' into the exhaust passage y. 

81. For lowering, the reversing valve occupies the posi- 
tion shown in Fig. 30 (/;). Live steam now passes through 



■rL7 T' 

m Vi .... 


the small port s into the [jurt •' ami thence through ' 
passage 1/ to the center iif the jiiston valve, converting it 
into an indirect valve ami thus reversing the motion of the 
engine. The exhaust from the engine passes through <■ and r' 
into the port c, and thence through the small port r in the 
valve to the exhaust passage _/". The elevator being under- 

balanced, the car descends by gravity, so that the steam 
ports need be uncovered entirely only for hoisting. Only 
enough steam to overcome the friction of the engine is 
needed in lowering, and for this reason the port s that admits 
steam for lowering is very small, being made up of a series 
of small holes drilled through the valve. The port r is 1 
structed in the same manner. 




83. When the car is at rest, the reversing valve occupies 
the position shown in Fig. 30 (f), where all ports are cov- 
ered. A motion of the reversing valve in an upward direc- 
tion will start the engine and hoist the car; a downward 
motion of the reversing valve will let the car descend. 

83. The stem R of the reversing valve {see Fig. 29) is 
attached to a lever L that is actuated by a rack Q and 

ion P from the shipper-sheave shaft 7", which latter is 
■also connected to the brake lever 0' by a chain II'. The 
Operation of the brake is plain fnun the drawing. 



84. The reverHing v^lvu in the machine shown 
Fig. 31 (fl), which is a Crane ■worin-geared steaiu el< 
vator, is somewhal different from the Otis valvi 
Ufscribed. Us action will be understood from Fig. 31 (*). (c), 
(rf), and (i-). Fig. 31 (i) is a vertical section through the 
two engine cylinders and the valve chest showing the steam- 
distributing slide valves /', I" in section and a front view of 
the reversing valve R, while Fig. 31 (d), {c), and (J) are 
transverse sections showing the three positions of the 
reversing valve. The action is as follows: Steam enters 
thnnigh the pipe a, Fig. 31 (c), the steam chest A. If the 
reversing valve A' is moved to the position shown in 
Fig. 31 {/>), the port c is opened, thus allowing steam to 
flow through the passage C into the cylinders, while the 
exhaust passes through passage B, port /', cavity A of the 
reversing valve, exhaust port f, and duct / into the atmos- 
phere. To slop, the reversing valve is moved to the position 
shown in Fig. 31 (c), when it closes the passages B and C. 
To reverse the machine, the reversing valve is moved to 
the position shown in Fig. 31 ((/). Steam then enters A 
through n, as before, but goes through port d and pas- 
sage 1} to the distributing valves /'. I'', while the exhaust 
passes through passage C and port c 

85. The manner in which the engine is reversed may be 
explained as follows: The port f and passage C connect with 
the steara passage s, and the port 6 and passage B connect 
with the steam passage t in the valve seat of each engine. 
With the reversing valve in the position shown in Fig. 31 (/'), 
the live steam is admitted through s into the central cavity c 
of the steam valves, while exhaust takes place through /. It 
is thus seen that the valves are now indirect. When the 
reversing valve takes the position shown in Fig. 31 (d), 
the live steara passes through 6 and Ji and through / into 
the steam valves, while now the exhaust steam passes 
through s into the cavity // of the reversing valve, and thence 
into ^ and/", and finally into the atmosphere. In this post' 
tion the steam valves act as direct valves and give a motii 


8 37 ELEVATORS. 49 

to the engines contrary to that obtained when the valves 
act as indirect valves. 

86, There is no brake shown on this machine. The 
worm having a sufficiently low pitch to make it self-locking, 
a brake is often dispensed with. When used, however, it 
consists of a wooden brake shoe, which is pressed against 
the wheel by means of springs and released by live steam. 

87. In the machine sh<.wn in Fit;. :'-'■ w'lifh '« ^ 'n-lt and 
spur-gear steam elevator built by the Otis Elevator Company, 


a rotary reversing valve is used. Its action is much the s 

as that of the Otis reversing slide valve previously described, *i 

88. Fig. 33 is an illustration of a belt and spur-gear i 
steam elevator. The machine is built by the Otis Elevator 
Company of Chicago, formerly the Crane Elevator Com- 
pany. The same kind of reversing valve is used in it as in 

the machine shown in Fig. 31. Among the controlling 
devices in this machine is to be noted the heart-shaped 
brake cam C, the deep notch of which marks the central, 
or non-driving, position of the controlling mechanism. 

89, Fig. 34 is an example of a belt and worm-geared i 
elevator built by The Whittier Machine Company, now con- 
solidated with the Otis Elevator Company. 

!)0. Motor Safeties.— Motor safeties are jirovided in all \ 
cases, either in the shape of limit stops of the ordinary yoke ] 




type, as shown in Figs. 29 and 33, or of special design with 
the same underlying principle as shown in Fig. 31 (a). 

91. The device used in the machine shown in Pig. 31 
has some additional features, and is, therefore, shown in 
detail in Pig. 35. 

The winding-drum shaft carries a pinion /, Fig. 3S («), 
meshing w Liagear/-. This latter gear has a seen nd pin- 
ion />', which is solid with it and meshes with another gear,i,'' 
mounted loosely on the winding-drLim shaft. This gearing, 
which is similar to the back gearing of a lathe, is such that 

52 ELEVATORS. . g 37 

the gear g' will make less than one revolution for the 
whole number of revolutions of the drum shaft necessary 
to lift the car to the top. To the gear g' is attached a 
drum having long slots [see Fig. 31 («)] into which are 
fitted adjustably the cams c, c' , shown in Fig. 31 (a) and 
Fig. 35 {b), (e), and {d). These cams are located on the 

drum li in diff<;rent pianos and havu two or more steps, 
as shown, and engage t-ventually each one of two sprinjj- 
actiiatcd lrii;gt-rs /, /' mmintcd in rockt-rs ;■, r' on a stud and 
ill plauL-s rurrcspondiny in thusi- of llu; cams. One of the 

an aim <j. in which is cnnnoctcd iIk- rod v leading to the 

§ 37 ELEVATORS. 63 

valve lever ;«, as shown in Fig. 31 (a). When the car 
reaches the top or bottom, respectively, of the hoistway, 
either cam c or c', as the case may be, engages its particular 
trigger / or /' and pulls or pushes the valve rod v. 

Fig. 35 {b) shows the position of the various parts when the 
car is about midway in the elevator shaft. Suppose now 
the car to go up; then, as it nears the limit of its upward 
travel, the cam c' will engage the trigger /' with the first one 
of the steps and thus move the valve rod v until the trigger 
passes over the first step, as shown in Fig. 35 (c). This will 
slow down the car; on a farther motion of the car the 
second step of the cam will come into contact with the trig- 
ger, pulling the valve rod still farther, thus slowing down 
the car still more, and so forth, until the steam valve is 
entirely closed and the car stops. 

92. The gradual choking off of the steam supply by the 
successive steps has the effect that with a heavy load on 
the car the latter will finally reach the top very much 
slower than with a light load, and may even stop short of 
the last landing. Conversely, if the apparatus is so adjusted 
that with a heavy load the car will finally stop at the lowest 
landing, it may do so with a light load, but only very slowly 
and even may not reach the landing. The apparatus illus- 
trated in Figs. 31 and 35 provides for these conditions, inas- 
much as it permits the operator on the car to operate the 
controlling device to some extent even after the automatic 
stop has performed its function. This is accomplished 
by making the triggers /, /' spring actuated. The springs 
will not yield to the action of the cams, the pressure being 
a transverse one, but they will yield if a pull or push, 
respectively, is exerted on the valve rod 7' by the operator. 
Thus, if it is found, for instance, that after the cam c' 
[see Fig. 35 (r)] has acted upon the trigger /' so as to slow 
down the car, the latter moves too slowly, the operator may 
pull on the rod t' and bring it into the position shown in 
Fig. 35 (d)y the spring of said trigger permitting this, and 
thus partly reopen the steam port. 

//. 5". v.— 15 

54 ELEVATORS. § 37 

93. The machine shown in Fig. 33 has a different 
arrangement for an automatic stop. Back of the disk d is a 
plate revolved from the drum shaft by a worm and gear 
(covered in the illustration by the case c). This plate has a 
spiral groove that moves a stud connected to the disk // in 
and out until it strikes and touches on adjustable stops and 
causes the disk ^and lever / to turn with it, thus centering 
the reversing lever r. 

94. 81aek-Cnble Safety. — Slack-cable safeties are gen- 
erally provided on all steam elevators, although shown only 
in Figs. 3*2, 33, and 34. They consist in all cases of a rod 
running across the under side of the winding drum and so 
arranged that it is depressed by the weight of any loose 
cable that may form. When so depressed, it releases a 
spring or weight, which, in turn, acts upon the controlling 
device, shutting off the steam. The aforesaid rod is seen in 
Figs. 33 and 34 at s and the weight at iv. In Fig. 3*2, the 
weight 1k\ when released, throws in a clutch that causes the 
limit-stop yoke to turn the valve rock shaft. 


D.l. The Mj K-ration of a steam elevator is exceedingly 
sinipK' and al «)ni e familiar to every one able to run a steam 
riv^inr. 'I'oo i^rrat care cannot be bestowed on the hoist- 
JMu ropts ami the various safety appliances; the weights .1 l-y steam elevators being usually great, the risk to 
': :ii..i !:tr is incurred by neglect on the part of the 
<;.-••,> . :■ i^ ( - ■:Tt'>j)(»ndinii'ly great. 

^M\, 1' l.( li -< ami elevators, attention must be j)aid par- 

* .; \ : : '.e .!; ivin- belt. A breakage of this ]>elt, it will 

' • - xe.i, ihr.'ws the ear and all there is upon it on the 

' ' ■'' '' - \\\\\\ disastrous results if the latter should prove 

• ■ '^i ' '• An (levator belt performs a duty much more 

^' •'"■ "rdinary beltiui^; it runs over a large and a 

:''.'";<\' A\u\ under an idler to give it as great as possi- 

au ui eoniaet (.)n the small pulley; it must also run in 

I > 1 

§ 37 ELEVATORS. 66 

opposite directions alternately, so that there is always con- 
siderable slip. Such a belt should, therefore, be of the best 
quality obtainable and should be well cared for. The 
leather used should be genuine oak-tanned stock ; the pieces 
should be cut from the hide in such a way that the hide 
center will be the center of the belt. The pieces should be well 
stretched before being made up. They should not be more 
than 50 inches in length, including laps, and should be joined 
by a so-called lock lap^ making a perfect joint. A straight 
lap should not be used under any circumstances. Besides 
being of best quality, the cement used must be very pliable 
on account of the short turn of the belt under the idler and 
over the small pulley. The belt should be riveted as a pre- 
caution against a lap becoming loose, so that the rivets may 
hold the defective lap together until it is discovered and 

Lacing belts must not be resorted to, as the laces soon 
break, due to running over the small pulley. 

It is recommended by elevator men to give the belt an 
occasional dressing with castor oil to keep it pliable. 


(PART 2.) 



!• Treating elevators in the order of their development, 
the hydraulic elevator would follow after the steam elevator, 
because the electric elevator is the latest competitor in the 
field. Nevertheless, as most electric elevators are of the 
drum type, and therefore similar in many ways to hand, 
belt, and steam elevators, they will be considered before the 
older type. 



2. The first mode of application of the electric motor to 
elevator machinery was simply a substitution of an electric 
motor for whatever kind of power was previously used for 
driving the line shafting of an ordinary belt elevator. The 
motor was started by an ordinary main switch and starting 
box and ran continuously in one direction, the ebvator 
being controlled in the same manner as other belt elevators. 
If such an elevator is not in constant use, the electric motor 
must be stopped and started frequently, which, with an 


For notice of copyriji^ht, see page immediately following' the title page. 


ordinary switch and liand starting bos, compels the operator 
to go to the starting box every time the elevator is used. 
To avoid this, the switch and starting box are operated by a 
hand rope running through the car in the same manner as 
the shipper rope, or to avoid the handling of the two ropes. 
the shipper rope may serve both for shifting the belts and 
for operating the switch and rheostat. 

3. General I>e*KTlpllon. — By introducing a reversing 
switch instead of the single switch, the motor can be 
reversed by reversing the current in the armature. The 
necessity for two belts, an open and a crossed one. is then 
obviated, and one belt between the countershaft and eleva- 
tor machine is sufficient, this belt being shifted from a Itiose 
pulley to a tight one to start the car in either direction, 
that is, up or down. 

4. Belt-shifting electric elevators being nothing but 
combinations of belt elevators with an electric motor, we 
can confine our remarks with respect to the various parts 
of these elevators to motors and controlling devices, all the 
other parts being the same as in ordinary belt elevators. 

5. Motors. — For belt -shifting elevators, continuous-cur- 
rent, constant-potential, shunt-wound, single-speed motors 
arc j-cncrally used, and since the motor starts without load, 
no riisli of current that might injure the armature takes 
|>l:ur Lil st^irtinj;. Any kind of alternating-current motor 
iii.iy ]>'■ iir;ril fi.r liclt-shifling elevators when the motor runs 
1 nniinu'Hisly. When, however, the motor is to be stopped 
;iiHl .■ilarli-il frequently, polyphase synchronous motors or 
iiidui'li'iu mutiirs must be used, because these motors will 
sUiri liy ihciiiM-lvfS, while single-phase motors will not. 

*{. CoiiD-oUliiK l>i.'v>ct-s. — Aside from the belt shifters 
III liill-shiftini; ilcviilnrs, the power control consists of a 
swill li .ihil a rhL'uslat. For combinations in wh i the 


motor runs continuously in one direction and is started and 
stopped only occasionally, the ordinary switch and starting 
box operated by hand are sufficient. If, however, the 
switch and rheostat are to be operated by a hand rope or 
other operating device from the car, special mechanisms 
become necessary, since the simple pull on the hand rope 
cannot give the necessary motions. To prevent a possible 
damaging rush of current in starting such an electric motor 
as is used in elevator work, the main switch is closed with 
all the starting resistance in the armature circuit, which 
resistance is then gradually cut out as the speed of the 
motor increases, until the motor is finally (when running at 
its normal speed) connected directly to the mains. After 
stopping, this resistance should all be in again, so as to 
make the apparatus ready for the nest start; and since 
starting may follow quickly upon stopping, this restitution 
(if the apparatus to its starting conditions after stopping 
must be effected 
quickly. When the 
switch and starting 
box are manipulated 
by hand, the above 
requirements can be 
easily fulfilled, but 
not when they are 
operated together 
from a hand rope. 
To obtain the re- 
quired motions, va- 
rious contrivances 
have been devised 
and are largely used. 
A few examples are 

7. MecliiuiieiLlly 
Operated l£lie«>- 
stalH. —The most 
natural way to 



gradually cut out the starting resistance as the speed of the 
motor increases is to mechanically connect the starting box 
to the motor shaft. Fig. 1 shows an apparatus made by the 
Automatic Switch Company and designed to be used with 
motors running always in one direction, that is, in our case, 
with an indirect-connected or belt-shifting, non-reversible 
elevator machine. The pulley Pis belted to a smaller pulley 
on the motor shaft or countershaft and drives a shaft 5 
having formed on it a two-toothed pinion /. When the 
motor is running, a rack R is drawn into mesh with the 
pinion / by means of an electromagnet £ energized by a 
coil in shunt with the motor circuit. As soon as the cir- 
cuit is closed and the motor commences to revolve, the 

rack ascends and with 
I it the contact bar /> that 
is carried on its upper 
end. The contact bar 
passes successively over 
the contacts C, gradu- 
ally cutting out resist- 
ance. As soon as the 
current is broken, the 
magnet is deenergized 
and the contact arm 
drops back, the rack A^ 
springing out of gear with the pinion. 

8. In connection with the starter shown in Fig. 1, a 
simple sna[) switch is used, such as is shown in Fig. 2; the 
action of this will be readily understood. It is operated 
either by hand or by a separate hand rope or cord rtinning 
parallel to the shipi)er rope in the hoistway. 

9. Fig. 3 is a diagram of an installation using the start- 
ing box shown in Fig. 1. Fig. 4 is a diagram of the connec- 
tions; this will j)rove useful to engineers wishing to drive 
existing belt elevators by an elec^tric motor. 

10. In case a belt-shifting elevator is to be run with a 
sini4;lc belt, the motor must be reversible. A reA^crsiiij? 

FlO. 2. 

8 38 ELEVATORS. 5 

switeli is then used instead of the single snap switch shown 
in Fig. 2. Such a reversing switch, made by the Automatic 
Switch Company, is shown in Fig. 5, which also gives a 
diagram of the connections. The reversing switch has 

four sets of contacts n, b, a', />', each consisting of three 
clips, and two blades Ji and B', which are insulated from 
each other. The clips are connected with the terminiils 
of the various parts {motur armature, field, resistance, 

and starter magnet), as 

shown. When 

the switc 

1 IS 

pulled up, blade />' con 

nccts the lliree 

clips at ti 


blade li' connects the thre 

i; clips at /'. Thi 

iiijows the 


rent to flow through the a 

mature, the sbui 

t field, and 




resistance, and the elevator ascends. When the reversing 
switch is pulled down, B connects the three clips at a' 
together and B' connects the three clips at b'. This 
reverses the flow of the current through the armature, 
because the wires on the switch that connect the upper and 
lower horizontal clips are crossed ; the current in the shunt 
field flows in the same direction, no matter whether the 
switch is up or down; hence, pulling down the switch 

reverses the motor. The terminals of the armature resist- 
ance are shown at / and 3; 3 and J, are the terminals of the 
magnet that throws the rack into and out of gear. With 
this explanation the student will be able to trace the path of 
the current without difficulty. 

11. It is often observed on opening the circuit that 
there is considerable sparking at the clips connected to the 
shunt field. Tliis is due to the .self-induction of the field. 
To reduce this sparking, it is a good plan to connect across 


the shunt a series of incandescent lamps having a combined 
voltage of from 6 to 8 times that of the line current; that is, 
in case a 110-volt lighting current is used, a series of, say, 
four 220-volt lamps is inserted, through which the induction 
current of the field is discharged. Since the starter is belted 
to the machine or countershaft, it will be reversed with it ; 
it must, therefore, be so arranged that it will lift the cross- 
bar i?. Fig. 1, no matter in which direction the motor runs. 
This is done in this kind of starter by substituting for 
the two-toothed pinion / an eccentric operating a pawl. 
Otherwise the ** reversible starter " is the same as the ** non- 
reversible " one. 

12. Another kind of mechanically operated starter is 
shown in plan and elevation in Fig. 0. It is made and 
patented by the Otis Elevator Company. Its action is dif- 
ferent from the apparatus described in the foregoing article 
in so far that it is not connected mechanically to the motor 
or countershaft but to the main-switch spindle, and the 
gradual cutting out of resistance is obtained by a dashpot. 
The following description is taken from the patent specifi- 
cations : 

A box A contains in its rear part jV resistance coils, and 
in its front part the operating mechanism, the essential fea- 
tures of which consist of a snap switch 7, an arm 2 for oper- 
ating the snap switch, and a brush-carrying arm S^ which 
brush of)erate8 in connection with a resistance device i^>; the 
brush arm S is, in the present instance, provided with a coun- 
terbalance 9 and controlled by a dashpot 4 ; arm S is mounted 
on a shaft 5, by means of which it is operated in the manner 
described later. 

The switch 1 comprises essentially a knife blade 7, 
mounted on a pivot 6*, adapted to engage and disengage 
the contacts 8^ <9, and connected to this knife is a cam IG hav- 
ing a notch ^7, into which projects the end of the arm 2 for 
moving the cam; the cam is further provided with recesses 
and projections AV, with which a spring catch A7 cooper- 
ates, under the stress of a spring 15' for holding the switch 

§ 38 ELEVATORS. 9 

in different positions and for making it complete its move- 
ments after it has been started, so as to produce the sudden 
engagement and disengagement in the manner well known 
in connection with snap switches. The arm 2 is rigidly 
connected to the shaft 5 so as to move therewith, while the 
brush-carrying arm 3 is loosely mounted on the shaft 5 ; inter- 
posed between the two arms is a catch, or stop, so arranged 
that the arm 2 may move independently of the arm 3 when 
the parts are in one position, but when it is moved in the 
opposite direction and the arm 3 is in another position, they 
will move together. This catch consists of a projection 2' 
on the hub of the arm 2 working in a slot 3' in the hub of 
the brush-carrying arm 3. 

The brush-carrying arm <^ carries a brush 11 adapted to 
bear on the resistance-contact device 10, and the contacts 
are arranged so that the contact 12 will permit a consider- 
able movement of the brush before any of the resistance is 
cut out. While the contacts 13 are connected by the resist- 
ances in box compartment A' in the usual way, the con- 
tact H is connected directly with the line; so that while the 
brush is on the contact 12 all the resistance is included in 
the circuit, and as it sweeps over contacts 13 more or 
less of the resistance is cut out until it bears on the con- 
tact Hy when all the resistance is out of the circuit. This 
resistance device 10 is made on the arc of the circle and is 
adjusted in the box by means of lugs and bolts engaging 
slots in the frame of the box. 

In the figure, the circuit is shown open and all the resist- 
ance is included in the circuit, the catch 2' bearing on one 
side of the slot 3' of the brush-carrying arm 3, holding the 
parts in the position shown. If, now, the shaft o is turned 
in the direction of the arrow, that is, to start the motor, the 
arm 2 operating through the cam 16 will move the switch 
blade 7 so as to engage the contacts <!?, the spring catch 15 
riding over the projection 18 and tending to complete the 
throw of the switch arm as it enters the adjacent depression 
on the other side of the projection 18, making a snap switch. 
The catch 2' moves through the slot 3 and leaves the 




brush -carniDg arm J free to move, which, under the influence 
of the cnunt«r balance f, ii commences to do at once, but its 
movement is retarded more or less by the dashpot 4- The 
[arts are so arranged that before the brush 11 moves off 
the resistance contact /.'. the switch 1 has closed the circuit 
through the contacts Sand the brush-carrying arm moves 
gradually over the resistance contacts, cutting them out, 
until the brush // bears on the contact H, by which time 
the motor has come up to speed. When the shaft 5 is turned 
in the direction opposite the arrow, thai is, to stop the motor, 
the projection ^' bears on the side of the slot S' so that as 
the arm S is turned to open the switch /, the brush // is 
m"Vi'<l over the resistance contacts, insuring the inclusion 
of the resistance in the circuit. It will be noted that the 
slot 17 in the cam 10 is of such dimensions as to permit the 
inclusion of a greater part of the resistance contacts before 
the knife Made 7 is actually moved from the conucts S. 

t3. Solenoid Rheostats 

Instead of the weight 9, 
Fig, fl, a solenoid is used in 
many starting devices. This 
permits the rheostat to be 
mounted separate from the 
switch, no mechanical connec- 
tion between the two being 
required. The switch alone 
is mechanically operated by 
the hand rope or other oper- 
ating device. Fig, 7 shows 
one form of solenoid rheostat, 
as manufactured by the Elek- 
tron Manufacturing Company. 
The armature current enters 
at the binding post 1, whence it 
goes to the contact arm A, 
through the series of resist- 
ances A*, and out at the binding 

§ 38 ELEVATORS. 11 

post 2. The solenoid current, taken from the main switch, 
enters at binding post 3, goes through the windings of the 
solenoid S, and leaves at binding post '2. As soon as the main 
switch is closed, the solenoid is energized and draws in the 
iron plunger P^ raising the arm A, and thus making the con- 
tact piece at the end slide over the sectors R' of the rheostat 
and cutting out resistance from the armature circuit. In 
order that this may be effected gradually, the other end of 
the arm A is connected by a rod with a piston fitting in a 
dashpot D. In moving downwards, this piston must dis- 
place the air in the dashpot, and the speed with which this 
may be done is regulated by the stop-cock C. To bring the 
apparatus back to its original position at the breaking of the 
circuit, the piston end of the arm is provided with a spring / 
that is put in tension while the resistance is cut out. On 
opening the circuit, the spring pulls up the arm and dashpot 
piston, and in order that this may be effected quickly the 
dashpot has a relief valve that will open while the piston is 
going up. 

14. The apparatus described in the foregoing articles as 
applicable to belt-shifting elevators are used for a number 
of other purposes, among which their connection with 
electrically driven pumps for hydraulic elevators is of 
special interest. 



16. The second step taken in the development of the 
electric elevator was the elimination of the countershaft and 
the tight and loose pulley, and the substitution therefor of a 
belt connecting the motor directly with the elevator machine. 
The mechanisms used in belt elevators for shifting the belt 
then became superfluous. Although the elimination of the 
countershaft seems a small and natural step to take, it makes 
a great change in the working conditions of the elevator, 



since in the belt-shifting types the motor starts without 
load, which is applied only after the motor has attained its i 
lal speed; white in the direct-connected type, the motor 1 
must start under load. There is nothing gained by having I 
the motor and the elevator separate and belted together, 
and therefore direct-connected belted elevators are i 
used; they are described here only to help us to arrive ' 
gradually at the form of elevator now commonly used. 


16. Connection of Motom and Mac-liines. — The work- 
ing conditions of the direct -connected belted elevator are 
not changed when the motor is coupled directly to the shaft 
of the elevator machine, and in the modern type of electric 
elevator this is always done, the motor being mounted un the 
same base with the machine, 

17. Motors.— Since in direct -con nee ted electric ele- 
vators the motor must start under load and must, therefore, 
have a strong torque, it must also get up speed rapidly 
though gradually. Of these two conditions the last-named 
one is fulfilled by peculiar controlling devices that are 
described below, while the first-named one is fulfilled by the \ 
construction of the motor itself, which is generally of the 

compound- wound type — a series-field coil serving to give i 
t necessary torque at starting and the shunt coil steady- 
ifthe field. The series coils are generally cut out when 
Binotor has attained normal speed, after which the motor j 
His as a simple shunt-wound motor. 
Of alternating-current motors, only the two-phase or 1 
(three-phase induction motors prove satisfactory for direct- ] 
'connected electric elevators, since they will start under load ! 
*.*ith sufficient torque. These motors behave, as far as their i 
'action in the elevator combination goes, just like shunt- 
*Ounii continuous-current motors. 

18. Transmittlnur IfevlK-es. — The transmitting devices 
stween the motor and car consist, with few exceptions, of 

§38 ELEVATORS. 13 

worm-gearing, drum, and rope. The worm-shaft is ahnost 
invariably coupled to the motor shaft by a flange coupling, 
serving at the same time as a brake pulley. Both single 
worm- and double worm-gearing are used, as will be seen from 
the illustrations given farther on, the double worm being 
used mostly on heavy machines, to avoid the end thrust of 
the worm-shaft. Such heavy machines are also frequently 
provided with back gearing. Ordinarily, however, single 
worm-gearing is used, great care and ingenuity being dis- 
played in the design of the step bearings for the worm. 

19, Counterbalancing:. — Direct-connected electric ele- 
vators of the drum type are always overbalanced. 

20. Controlling Devices. — The power control of direct- 
connected electric elevators is entirely electrical, there 
being no belts to shift or similar mechanical operations 
to perform; but, besides breaking the current, the motor 
must be reversed. Hence, besides the simple snap switch 
and rheostat already mentioned in connection with belt- 
shifting electric elevators, a reversing? s^vltch. or pole 
changrer is needed. 

In elevator practice, the complete apparatus necessary to 
control the electric motor — the power control, as we have 
called it — is called a controller, especiallyif the various parts 
of it are built together in such a way as to make a separate, 
self-contained piece of machinery. A number of different 
forms of such controllers are used by the various manufac- 
turers of electric elevators, and they will be described with 
the various designs shown. 

31. Brakes. — The braking arrangements used are either 
entirely mechanical, that is, such as are used in connection 
with belt and steam elevators, or electrical mechanical, or 
wholly electrical. 

33. OperatlnjUf Devices. — In the majority of electric 
elevators the operating devices are mechanical, such as hand 
ropes, hand wheels, and levers. Electrical operating devices 

H. S. V.—I6 

§ 38 ELEVATORS. 16 

are being introduced, however, with success in connection 
with the magnet system of control, which is described later. 

23, Motor Safeties. — Motor safeties are used in various 
forms; they are either mechanical or electrical or both. 



34. The examples of electric elevators here given do 
not represent all the various designs in the market, nor does 
the order in which they are described indicate any superiority 
of design of one make over another. A careful study of 
these will give a person enough insight into the construction 
and operation of this class of machinery to enable him to 
handle other makes of machines. 


35. Motors. — Ffg. 8 is an end and side elevation of an 
electric elevator made by the Elektron Manufacturing Com- 
pany. The motor is the well-known Perret multipolar 
machine, shunt-wound. 

36. Transnilttiiij^ Devices. — The transmitting devices 
are single worm-gearing, drum, and rope. The arrange- 
ment of the step bearing of the worm is shown in Fig. 9. 
Alternate phosphor-bronze and steel disks are used to dis- 
tribute the wear. The worm-shaft is attached to the motor 
shaft by means of a flange coupling /% which serves at the 
same time as a brake pulley. 

37. Simple Controller. — The Elektron Manufacturing 
Company uses various kinds of controllers for various kinds 
of elevators. The simplest arrangement used is a double- 
throw switch attached to the hub of the shipper sheave .S\ 
Fig. 8, and a solenoid rheostat placed anywhere conveniently 


The switch consists of a casting A, Fig. 8, supported 
on the frame of the machine and carrying four sets of 
clips (T,, C,. and t'/. C,', to which the necessary line, field, 
armature, solenoid, and electric-brake connections are made 
as shown below. The switch blades /?,, B, attached to the 
shipper sheave engage the clips C,. C\, or C,' CJ for the up 
trip and the down trip, respectively. In Fijj. 8 the blades 
are shown in their neutral position; that is, when the ele- 
vator is at rest. It will be seen that to start the elevator 
up or down, the sheave with the blades must be turned 
through an arc of 135", the clips being set at right angles. 
This long travel is given for the purpose of giving the rheo- 
slat arm time to fall back into its starting position before; 
the current in the armature can possibly be reversed 
helps to reduce sparking and flashing at the clips. 

28. Onllnary Itrake. — T!ie brake used in these machines 
is, for ordinary service, a simple mechanical one, which 
released by a cam on the shipper sheave through a system of 
levers and applied by a weight, as with belt elevators, 
passenger service, an electrical-mechanical brake is ut 
which is released by an electromagnet and applied 
gravity. This arrangement is shown in Fig, 8, in wl: 



the brake magnet is markeil li; the rapidity of action of 
the same is regulated by a dashpot D. 

29. Fig. 11 is a diagram of the electrical connections 
between the switch, rheostat, brake, and niutur. It will be 
useful to follow out these connections. The lines are con- 
nected through the fuses /",_/" and the double-pole switch s to 
the elevator switch at the binding posts /,, and /,,. Sup- 
posing the blades of the switch to be thrown to the right, 
that is, across the clips L\ and C,. and the current to enter 
at the binding post /.„ then it passes first to clip I of the 
set C"„ whence it divides by means of the switch blade 
among the clips 2, J, and 4- From ■! it passes to binding 
post Z„ thence through the field windings of the motor, 
back to the binding post /,„ thcnc- to the clip b of set t'„ 

§ 38 ELEVATORS. 19 

over the blade crossing this set of clips to clip a^ thence to 
binding post L^ and to the line, thus completing the shunt cir- 
cuit for the field. From clip S the current goes to the binding 
post Z„ through the solenoid windings of the rheostat R to 
the binding post r, of the rheostat to the binding post Z, of 
the switch, to clip c of set C, over the blade to the clip a^ 
to the binding post L^ to the line, thus completing the 
circuit through the solenoid. From clip ^ the current goes 
to binding post /,„ thence through the armature of the motor 
to the binding post r, of the rheostat, through the lower 
half of the resistance, through the rheostat arm and the upper 
half of the resistance to binding post r,, to A,, r, a, Z,,, and 
line, thus completing the armature circuit. Throwing the 
blades to the left, we will find, in following out the three cir- 
cuits again, that the current traverses the field circuit in 
the same direction as before, but that the current in the 
armature is reversed, thus reversing the motor. The 
electromagnet windings of the brake are in shunt with the 
solenoid circuit, as is easily seen from the diagram. 

30. The operation of this elevator is as follows: When 
the shipper sheave is thrown over to the right or left, the 
brake magnet is energized and tends to slowly release the 
brake, since the dashpot prevents too sudden a release; at 
the same time the solenoid is energized. This tends to 
slowly cut out the resistance from the armature circuit; 
the dashpot prevents too quick an action, and it is so 
adjusted that all the resistance will be cut out by the 
time the motor reaches its normal speed. Upon breaking 
the circuits, the brake is at once applied and the resistance 
arm drops back into its original position, ready for another 

31. Dynamic Brake. — On high-speed elevators, in 
order to get a particularly smooth stop, the Elektron Man- 
ufacturing Company uses, in addition to the electrical- 
mechanical brake, a so-called dynamic brake, which, indi- 
cated in Fig. 8 at R, is usually placed on a bracket between 
the shipper sheave and worm-gear case. It is shown in 


(IrtatI in Fig. li and c^msists of a switch lever L, actuated 
by a cam on the operating sheave, and a variable resistance. 

P»o. II 

■-■led to the system that the arma- 

■ ugh it immediately after the cir- 
-■■I 1.1 Slop the elevator, thus acting 
■ ic motor acting as a dynamo and 
^ii tbt rtsisiance. This has the 

■ lown quickly but smoothly, like a 
than an ordinary frictional brake. 

< '!■ is made still more marked by 
:illy cut out of the armature short 
s down, the cam operating the 
: "d as to first cut in all the rcsi'it- 
itiain circuit is broken; on being 
Jl^ LUc i.[K:rator, the switch lever is caused to 

§ 38 ELEVATORS. 21 

brush over the resistance contac^ts, thus gradually cutting 
the resistance down to zero. Of course this short circuit is 
opened before the elevator is started again. As has been 
said, the dynamic brake is used only in addition to the ordi- 
nary brake, the latter being necessary to hold the car sta- 
tionary after it has been stopped. 

32. Fig. 13 shows diagrammatically the connections 
when the dynamic brake is used. The field must necessa- 
rily remain excited after the armature circuit is broken and 
the armature short-circuited, in order to make the motor 
act as a dynamo. The field is, for the sake of simplicity, 
kept excited all the time, but in order to cut down the 
current thus constantly wasted while the elevator is stand- 
ing still, a resistance is inserted in the fields. When the 
elevator is started, this resistance is short-circuited, thus 
giving the fields the full current due to its windings and, 
consequently, the full torque available. When the elevator 
is stopped, the resistance is cut in, choking the field current, 
but leaving it strong enough to give sufficient magnetism 
to get a dynamic-brake eflfect. 

33. Speed Ke^^iilatin^ Controller. — Another type of 
controller used by the Elektron Manufacturing Company is 
shown in Figs. 14 and 15, while the diagram of connections 
is given in Fig. 16. It is evident that the combinations 
described in the previ<nis article do not allow of any regula- 
tion of speed, the motor being simply shunt-wound w-ith 
an unchangeable field. The purpose of the arrangement 
now to be described is to give speed regulation, which is 
accomplished by a changeable resistance in the field. The 
controller is mechanically operated. 

As seen in Fig. 14, there are two cams /and //operating 
the armature and field-resistance arms A^^ and A^ resj)ect- 
ively. Both arms are provided with dashpots />„ and D^, 
Two more cams /// and /J\ shown in Fig. 15, operate the 
reversing switch, or pole changer, P\ the one cam is 
intended to throw the switch for going up and the other for 
going down. While not visible in the illustrations, there 


sre other cams that operate various knife switches. All 
lliese cams are mounted on the shipper-sheave shaft 5. 
The brake is the same as in the previous design. 

34. Fig. Ifi is a diagram of the connections for this 

:onlroller, {a) shows the external connections between 

I motor, brake, and connection board Ji\ (d) gives the internal 

1 38 ELEVATORS. 25 

connections between the connection board />' and the various 
clips and resistance blocks inside the controller. By swing- 

ing the shipper sheave to the rinlit or left, swilch blades con- 
nect the clips a and d, c and d, and r andy^ completing the 

26 ELEVATORS. § 38 

circuits. Thus, supposing the current to enter the system 
from the line at the binding post i, it goes to the clip f, over 
a blade or knife to the clip/*, thence to the pivot/, of the pole 
changer, where it divides. One branch goes through the 
pole-changer arm r, and the armature resistance to binding 
post ^, thence through the armature back to the binding 
post J, thence through the other pole-changer arm r, to the 
pole-changer pivot /„ to the clip ^, over the knife to the 
clip iJ, thence to the binding post 4» and back to the line, 
thus completing the armature circuit. The other branch of 
the circuit goes from /, to the binding posts 5 and 6, which, 
ill turn, are connected, respectively, to the brake-magnet cir- 
cuit and the shunt-field magnet circuit. The other terminal 
of the brake-magnet circuit is connected to the binding 
post 7, whence the current flows over clips c and J, and b 
and a to the binding post 4, and back to the line. The 
other terminal of the field circuit is connected to the bind- 
ing post 8, whence the current flows through the field 
resistance to /„ ^, a^ post 4, and back to the line. 

35. The cam /, Fig. 14, on the shipper-sheave shaft is so 
arranged that after the circuits are closed the armature- 
resistance arm A„ is free to move, which it does slowly under 
the retarding influence of the dashpot /)„, gradually cutting 
out resistance until at the normal speed of the motor all resist- 
ance is cut out. After turning the shipper sheave a little 
farthrr, the cam // controlling the field-resistance arm Ay^ 
is released, but is retarded by the dashpot />/. Thus the field 
resistance is slowly ci/t in, weakening the field and speeding 
up the motor. 

30. Another pair of clips ^i^'-and //, Fig. 1(>, is so connected 
that when a switch blade is thrown across them, the arma- 
ture is short-circuited throuji^h the stopping resistance. This 
switch j,'"// is closed and the armature short-circuited when 
the other circuits are opened. 

37. Motor Safeties. — The usual motor safeties, viz., 
limit stops and slack-cable safety, such as we have met in 

§ 38 ELEVATORS. 27 

connection with belt and steam elevators, are used in the 
Elektron elevators. Their arrangement is shown in Fig. 15. 

38. Another motor safety used is in the shape of a switch 
controlled by a centrifugal governor running in unison with 
the car, and which opens a switch in the brake circuit when 
the car attains undue speed. This safety is indicated at Y 
in Figs. 11 and 16, and is connected in series with the brake 
solenoid by opening the solenoid circuit at point / and insert- 
ing switch F, as indicated by the dotted lines. 


39. Motors. — Fig. 17 shows one of the standard machines 
built by the A. B. See Manufacturing Company. A bipolar, 
drum-armature, compound-wound motor is used. 

40. Transmitting: Devices. — Among the transmitting 
devices, the step bearing shown in Fig. 18 is of peculiar con- 
struction. Both steps, that for the up trip and that for the 
down trip, are located at the free end of the worm-shaft and 
are easily accessible. The one is adjustable by means of the 
plug P in the cap C, while the other is made so by means of 
the nut A^on the threaded free end of the shaft. The other 
end of the worm-shaft passes through a stuffingbox S, as in 
other machines. The worm and lower part of the worm- 
wheel are constantly running in oil. 

41. CJontroller. — The controller, as shown in Fig. 17, is 
placed on top of the motor and consists of a box with three 
compartments, one of which is accessible from doors (?, and 
another one from similar doors on the opposite side. The 
first, shown open in Fig. 19, contains the main reversing 
switch MsLTid three snap switches N, A'\ and I/, the blades, or 
knives, of the latter being mounted on the same lever, but 
insulated from one another. The switches are operated by a 
bar By which, in turn, is linked to the rack A\ Fig. 17, and 
operated by a pinion P fastened to the shipper sheave S. 
The opposite compartment contains a solenoid dashpot, a 


resistance Ifver, and resistance inntactH very much the 
as those shown in Figs. 7 and 111. The third compartmcni is 
located between the first-named two and contains resistance 
coils of German-silver wire. The walls of the compartments 

are cut away wherever they are not needed for the support of 

contacts or mechanisms, so astogive venlilalion in the resist- 
ance coils; the doors and sides of the controller are per- 
forated, as shown in Fig, ]7, for the same purpose. 



43. Brake. — The brake used in this machine is con- 
trolled mechanically and electrically. A spring -cushioned 
push rod r. Fig. 17, is operated by an arm fastened to the 
shipper sheave and forces the brake lever down to apply the 

brake. A solenoid E holds off the brake as long as there is 
corrent in the armature with which the solenoid is connected 
iaieries. A weight If' applies the bruke, when the current 
if brokeo. There is also a dynamic-braking effect, the 

H.S, V^i7 

30 ELEVATORS. g 38 

armature being short-circuited through resistance when 
current is shut off from the machine. 

43. Motor Haftrtles. — This machine is particularly well 
provided with motor safeties. Not only the usual traveling- 
nut, limit-stop, and clutch-operating slack-cable safely are 
provided, but an extra limit switch is also provided, which 
breaks the current through the armature and brake solenoid 


at the limits. )f car travel. Thisswilfh s. Fig. 17, located on 
the wnriii-yeiir casing lu-|.>w the drum shaft, is spring actuated 
and tripped hy a .-itop on a gear,!,'-, wliicli is one of a suitable 
train of gears driven fnmi Unr ilruni shaft. The weight ((' 
ihn-ws in thi: chifli lliat ii.niurls Uii: drum shaft with the 


shea VI 




§ 38 ELEVATORS. 31 

44. Electrical Connections. — Fig. 20 is a diagram of 
the electrical connections. The contact pieces are marked 
in the diagram the same as in Fig. 19. The circuits for the 
position of the controller shown in this figure are as follows. 

45. Armature Circuit, — In the armature circuit the 
current passes through the -|- line to clip S\ from clip 3 to 
clip J/, over the blade of the switch; from clip 4 to clip 10 ; 
and from clip 19 to clip 18 over the switch blade, which is 
open only when the car overtravels the normal limits of 
travel ; from clip 18 the current passes through the series 
coil of the electric brake to clip 5 and then to clip ^ over the 
switch blade; from clip 6 it passes through the series field 
of the motor, through the armature resistance and series 
coils on the armature resistance solenoid to clip 10 and 
then to clip 9 through the switch blade; from clip it 
passes through the armature to clip 12 \ from clip 12 to 
clips 13 and H\ from clip H to clip 7; and from clip 7 to 
the — side of the line. 

46. In the armature circuit, when the pole changer is 
reversed from the position shown in Fig. 19, the current 
passes from the + lii^e to clip 3 and then to clip 4 ; from 
clip Jf. to clip 19 and then to clip 1S\ from clip 18 to 
clip 5 and to clip 6\ frorn clip 6 to clip 10 and on to clip 11 \ 
from clip 11 to clip 12 and then through the armature, in a 
reverse direction, to clip 9 and then to clip S\ from clip 8 to 
clip 7 and then to the — side of the line. 

47. Dynamic-Brake Circuit. — When the controller is in 
its neutral position, that is, when the current is shut off 
from the machine, clips 1 and 2 are bridged by the switch 
blade C/and the motor is short-circuited through the resist- 
ance, passing from clip 1 through the armature and then 
through the short-circuit resistance a to clip 2, 

48. Electric Brake. — The shunt coil of the electric brake 
obtains its current from clii) 77, clips 77, /.V, and V-^ being 
bridged by one switch l)hi(lc, which is operated by the 
stop motion mentioned in Art. 4S and which stop motion 

§38 ELEVATORS. 30 

automatically breaks connection between clips 77, IS^ and 10 
when the car overtravels its normal limits. This switch is 
essentially an automatic safety switch, for it not only 
breaks the line current before it passes through the arma- 
ture, but also breaks the current flowing through the shunt 
coils of the brake solenoid. 

The + side of the shunt coil is connected to the separate 
clip 17 instead of to the clip IS in order that upon breaking the 
circuit the armature circuit may be disconnected from the 
electric-brake circuit, thus allowing the brake to act at 
once. Otherwise, the motor still running would send 
enough current through the shunt coil of the brake solenoid 
to keep it energized and thus prevent its action. The elec- 
tric-brake circuit is, therefore, from clip 17 through the 
shunt coil to the terminal J/', and from J/' to clip 8 or yj; 
from clip IS to clip H, or from clip 8 to clip 7, and thence 
to the — side of the line. 

49. Path of Current in Starting Box. — The shunt coil 
of the solenoid /?, Fig. 20, gets its current from clip 5\ 
and after the current passes through the coil it enters 
clip 21, The switch blade, or knife, that bridges clips 20^ 
21^ 22 is drawn out of contact with the clips wiien the 
plunger of the solenoid reaches the end of its travel, when 
all the resistance in the armature circuit is thus cut out. 
Before the switch blade is removed, the current crosses 
on it to clip 22 \ from clip 22 it passes to clip i6\ and thence 
to clip 7, whence it goes to the — side of the line. 

When the contact is broken, the current is forced to 
pass from clip 21 to and through the resistance d from the 
terminal M" to the terminal S\ from the terminal S it 
passes to the terminal M\ then to clip <S\ and so on to the 
negative side of the line. The resistance li is introduced 
in this circuit for the purpose of reducing the heating in the 
shunt coil and to reduce the current consumption after the 
solenoid has done its maximum work. 

60. Field. — The field circuit of the motor is as follows: 
The current passes from the + line to clip *i and thence 

34 ELEVATORS. § 3« 

through the field to the terminal F of the resistance //. 
From F it passes to clip 20 and thence to clip 22^ to 
clip i^, to clip 7, to the negative side of the line. When 
the armature resistance is all cut out, contact between 
clips 20, 21, and 22 is broken, and the current is forced 
to pass through the portion of the resistance between the 
terminals /^and 5 to the negative side of the line, provided 
the parallel connections from clip 15 to clip 16, or at the 
limit switch from clip 23 to clip.^^, are broken. This resist- 
ance weakens the field on the motor and causes it to run 
at a higher speed. The contact between clips 23 and 2J^ is 
automatically made and broken when the car gets within 
about a floor from the top or bottom of its travel, and by the 
same stop motion that operates the limit switch. When 
the switch blade connects clips 23 and 21^, the resistance in the 
field is short-circuited; the field strengthens and the motor 
slows down. The switch blade bridging clips 15 and 16^ 
although situated at the machine, is withdrawn directly by 
the operator in the car during the last few inches of travel 
of his controlling lev^er, and he is thus enabled to weaken the 
field on the motor and run at a higher speed, but only after 
the car passes the first floor from the top or bottom and 
after all the resistance is cut out of the armature circuit. 

/>t. In some of the See machines, the field is broken 
every time the motor stops. Fig. 20 is a diagram of a 
mathine where the field is on all the time. Whether the 
field is to he left on or off is determined by the duty of the 
elevator. When the high-speed attachment is left off, a 
cliange in connections from those shown in Fig. 20 is made, 
1^^'g. 20 being a diagram of connections for a high-speed ele- 
vator running 250 feet per minute and over. 


5*5. Motor. — Tlie Otis IClevator Company makes a num- 
ber of stvles of ekn^tric elevators. Thev are all of the drum 
t ype, but have various kinds of controlling devices. Figs. 21 

§ 38 ELEVATORS. 3.5 

and 23 illustrate what may be termed the standard type of 
Otis elevators. 

The motor used is the Eickemeyer bipolar, drum-armature, 
compound -wound type, the series coils of the field being 

cut-out after the starting resistance has all been cut out, 
that is, when the motor has acquired normal speed. This is 
done both on the up and down trip i)f the car. 

53. Ti-ansmlttinsr Devices. — With regard to the trans- 
mitting devices, it may be mentioned that either single or 
double worm-gearing is used, the latter for the larger sizes 
generally. In connection with the single worm a peculiar 
kind of step bearing is used. The purpose of this arrange- 
ment, shown in Fig. 23, is to increase the bearing surface, 
without enlarging the diameter of the step, by dividing the 
pressure between two surfaces, viz,, the end surface s of the 
shaft and the ring-shaped surface s' of the bushingj'?. Now-, 
it is well known to any mechanic that it is ne.\t to impossi- 
ble to make the wear equal on two such separate surfaces 
unless special provision is made for it. This provision con- 
sists in this case of a couple of small levers /, / having three 

§ »8 ELEVATORS, ;i7 

points each. One of these points, in the middle <>{ one side 
of the lever, rests against an adjusting screw 5, which is 
provided for the purpose with a circular groove. Of the 
other two points on the ends of the other side of the levers, 
one rests on the step plate /'and the other on the bushing fl. 
If the bushing wears faster at s' than the step plate wears 
at s, the shaft will move to the right, which will cause the 
levers to press on the bushing, and vice versa. Thus, the 
pressure is equally distributed over both surfaces j and s'. 
The screw J> serves to take up the wear. The little equal- 
izing levers /, /are held in place by being placed in slots in 
the sleeve or bushing /?, and by a pin/ that fits into semi- 
cylindrical grooves in the end of the levers. Buffers between 
the worm-gear and drum are used on all Otis electric eleva- 
tors to absorb vibration. 

54. ControlUnfT Devices. — The controller of the Otis 
elevators is box-shaped and is usually mounted on top of the 
motor, as shown at C in Figs. 21 and 'i'i. It is operated by 
a rod R attached to the shipper sheave, which rod has an 
arm A on the other end, which engages by means of a part a 
with another arm or crank, hidden underneath the arm -•/; this 
crank is fastened to a shaft that reaches inside the controller 
box. In Fig. 24, which is a drawing showing the interior 
mechanism of the controller, this shaft is marked s. For 
clearness, the two parts (/') and (i) of the mechanism are 

g 38 ELEVATORS. 39 

shown apart, while in reality part (r) is in front of part (/'). 
Vig. 24 (a) is a detail view of some of the parts not very 
clearly shown in (^), where they are shown in dotted lines. 
The following is a description of the mechanism: the por- 
tion (c) contains the reversing: d ruin mounted on and keyed 
to the shaft s; it has four contact plates insulated from one 
another. On these contact plates, of which two are long and 
two short, there rest four brushes J, 2^ J, and 4» 90"^ apart. 
By turning the drum to the left, brushes /, <? and J, 4 ^re 
made to rest on the same long contacts; while by turning 
the drum to the right, brushes /, 4 and ,?, S are brought into 
connection. The brushes are so connected to the armature 
and line that by turning the drum as aforesaid, the current 
in the armature is reversed. This will be plain from the 
diagram of connections given in Fig. *Zf'}. Behind the drum 
there is also fastened to the shaft s a lever /, Fig. 24 (//) 
and (/;), carrying pins/ and /', which, when the shaft s is 
turned, engage a tooth / formed on a plate i' pivoted at //. 
The plate 7' carries another plate t*' having notches into 
which falls the end of a spring-actuated bell-crank lever o. 
By turning the shaft s, the plates 7' and i'' are first turned 
around // until the end of the lever o rides on one of the 
sharp corners of the plate i'', whereby the spring of lever o 
is stretched. Turning the shaft s a little farther makes the 
end of the lever engage the inclined planes ;/ or //', which 
are so located that the spring causes the plate 7'' to make an 
additional quick rotary motion. 

On the pivot w is fastened the blade X' of the knife switch 
shown in the upper left-hand corner of Fig. 24 (/;), and the 
quick rotary motion of the plate i'' causes this blade X'tc. snap 
between the clips c and c' of the switch. It is evident that 
on returning the mechanism to its middle position, the same 
snap action is caused by the two middle inclined planes c^f 
the plate v\ so that the switch blade X' is quickly withdrawn 
from the clips r, c\ thus avoiding the formation of arcs; 
this is really the main object of the snap switch. 

The other end of the lever / is formed into a cam of pecu- 
liar shape, which engages a pin r of a double-armed lever / 



pivoted ai _^- This lt-vt;r / li:is fastfrn;d to its lower end a I 
curved magnet core entering a solenoid O, as well as a t'oii- I 
tact arm P arranged to slide over resistance contact blocks R. I 
The greater part of the weight of the magnet core and arm P J 
is counterbalanced by a weight tc on the other arm of the I 
levery, so that when free to move, the magnet core, while I 
having the tendency of swinging out of the solenoid, will be I 
pnlied back into the same as soon as the current will pro- I 
duce enough magnetism to overcome the unbalanced weight ] 
of the core and the arm P. The lever/" becomes free to J 
move, however, only after the shaft s has been turned ] 
enough to make the circuit at the snap switch, the cam on I 
the lever /holding all parts in position until then. I 

55. Supposing that the solenoid and the resistance Ji I 
are in series with the armature, it will be seen that the I 
operation of this apparatus is as follows: First the cir- J 
cuits are closed with all the resistance in the armature I 
circuit and the motor starts up. By the time the motor I 
has gained some speed the lever / is set free, and if the 1 
speed of the motor is such that the counter-electromotive 1 
force is enough to cut down the armature current to the 1 
desired amount, the solenoid will not hold the core, the I 
latter will swing out, and the arm J' sliding over the con- I 
tact blocks R will gradually cut out the starting resistance, I 
Should for any reason the armature current increase abova I 
the normal, the solenoid will pull back the core, throwing I 
resistance into the armature circuit. It is thus seen that I 
the solenoid performs two functions: first, that of cutting' 1 
out the starting resistance; and second, that of a safety I 
device. In stopping, the lever / is brought back into the I 
original position by means of the cam on the lever /, making ■ 
the arrangement ready for starling again. I 

56. The diagram of connections given in Fig. 25 will be " 
readily understood. It is to be noticed that the series 
windings of the field are cut out after all starting resistance 

is cut out, A safety wire s connects the end of the solenoid 
with the first resistance contact. This wire will keep the 

42 ELEVATORS. § 38 

circuit closed even if, for some reason, the contact brush of 
the solenoid lever should fail to provide sufficient contact 
and thus stop the motor. The resistance coils are placed in a 
compartment of the controller box back of the mechanism 
shown in Fig. 24. 

57. Brakes. — The brakes on the Otis elevators are of the 
band type. In the simpler forms, a steel band faced with 
leather encircles the pulley and is so connected to a weighted 
lever that the weight applies the brake. The lever is linked 
to the controller rod in such a manner that when the shipper 
sheave is turned either to the right or to the left the brake 
is released. 

58. For high-speed service elevators, such as are shown in 
Fig. 22, a different kind of brake is used, for the reason that 
in such elevators the car must be stopped almost instantly 
without any possible slipping when the limits of travel are 
reached; while at any floor stop, midways of the travel, 
such instant stoppage is not so essential. The brake is, 
therefore, so arranged that it will be set in action by the 
limit stop much quicker and more effectively than by the 
ordinary device. The arrangement is shown in detail in 
Fig. 2(). 

On a stand ./ is a bearing a in which a short shaft s can 
revolve. To this shaft is keved a crank-arm C, which in 
turn is connected by a rod /v to the yoke of the limit-stop 
device L, Fig. 22. On the shaft .c there is also keyed an 
eccentric /s carrying another eccentric Zs'; the strap /) 
encircling this outer eccentric is connected by a spring- 
cushioned rod ^/ to the brake lever, and to it is also fastened 
the shipper sheave .V, so that the latter, with the outer 
eccentric, turns upon the inner eccentric as a pivot. The 
outer eccentric has an arm C\ Fig. 20, connected to the 
controller crank by a rod /v'. Fig. 22. To stop the car at 
intermediate landings, the brake is applied by turning the 
shij)])er sheave into the i)osili()n shoAvn in the figure, the 
outer ('C(HMUric ])ressing down on I lie brake lever. When, 
however, the limit stop is set in action, the inner eccentric 


is turned, which, having a greater throw than the outer 
one, gives more pressure to the brake. 

59. Another feature of the brake shown in Fig. 20 is 
the aafety magnet ,1/. This magnet serves to automat- 
ically apply the brake if the current should for any reason 
be interrupted in the system, and is placed in shunt with 
the motor, together with a so-called potential switch {of 
vhich we shall speak later), as shown in Fig. ^5 in dotted 
lines. The armature m of this magnet has a projection. 

I nose, )/ whifh Tiormally, that is, when a current of suflli- 
bt magnitude circulates through the magnet winding, 
Bs in suspense a weight ITconiiectod to the free end of 
nrakc band, as shown in Fig. %<>. As soon as the cur- 
K falls below the normal, the weight I/' trips the arma- 
J.ff< and tiginens the brake band. After the trouble 
is safety arrangement to act has been remedied, 
; U replaced into the [wisiiion shown in Fig. -.Jti 


by operating the brake in the regular way. Dynai 
braking is also report eel to. 

GO. OpemtlMS Devices, — For standard passenger a 
freight elevators, the simple hand rope is generally used : for ■ 
high-speed elevators, hand-wheel devices or levers are pre- 
ferred. To prevent accidental reversal of the motor in 
stopping, the tripping device (the lever / and the plate :) 
shown in Fig. H has considerable lust motion, or backlash. 

fil. Motor Safeties. — Besides the safety magnet brake 
.. above described, the usual limit-stop arrangement, consisting 
I of yoke and traveling nut, and a clutch operating the slack- 
cable safety, the Otis Company generally installs with the 
magnet brake a so-called poienilal switch. This switch, 
shown in detail in Fig. «7, has three blades F,, F„ F,, with 

•nrn-s[^'n!ing double clips /?,. />,. />.. of which xhf 
(frt ar- ■ ■nnected. as shown in Fig. «•>, lo the line 
and :t:v third P, to a wire leading to about ihe_ 
i the starting resistance. Blades F, and F^ 

§ 38 ELEVATORS. 45 

connected to the motor circuit as shown, and 7% to F^. An 
electromagnet E placed in the shunt across the line in series 
with the safety-brake magnet holds the blades F^ and F^ in 
contact with the clips /),, D^ by means of a catch c on the 
armature of the magnet engaging a projection d on the 
fulcrumed lever carrying the blades. A spring s counter- 
acts the magnet and causes the blades F^, F^ to leave clips 
i>„ Z>, and the blade F^ to engage the clip Z>, when the cur- 
rent in the magnet windings falls below the normal. This 
has the effect of breaking the main circuit, releasing the 
safety brake, and thereby short-circuiting the armature 
through more or less of the starting resistance, according to 
the position of the resistance arm at the time. This short- 
circuiting acts as a brake on the motor, as is well known. 

62, The usefulness of the potential switch extends beyond 
the use just explained. In Fig. 28, a method of connecting 
up the potential switch is shown, by which the potential 
switch not only performs its function in case of a fall of 
electric potential, but also in case of an undue increase of 
current in the line. For this purpose the switch magnet E, 
Fig. 27, has two windings with opposite magnetizing effect. 
One winding (the one next to the armature of the magnet) 
terminates in the binding posts //, //', while the other ter- 
minates in binding posts /, /'. These posts are, respectively, 
connected so as to throw the magnet winding ////' in series 
with the armature of the motor, and the coil / /' in series 
with the safety magnet brake, as in the previous case. 

The coils of the electromagnet are so proportioned that 
under normal conditions the shunt coil I /' gives a stronger 
magnetic field than the series coil // //', and since they are 
wound in opposition to each other, the shunt coil will thus 
normally hold the switch closed. But if the potential in the 
line falls below the normal, the switch will be opened, the 
magnet not holding against the spring. Again, if the cur- 
rent in the armature circuit rises above the normal, the 
series coil of the magnet will produce a stronger field than 
normally, with the effect of weakening the field produced by 

H.S. V,—i8 




the shunt coil, so that eventually the magnet will be demag- 
netized enough to let go of the switch lever. It is thus seen 
that the switch operates not only under a fall of potential 

Fig. 28. 

but also under an excess of current. The screw S shown in 
Fig. 27 serves to regulate the shunt field by screwing it in 
or out, decreasing or increasing, respectively, the resistance 
of the magnetic circuit of £. 



6t^. While direct current is preferable for the operation 
of electric elevators, in many cases alternating current is 
the only source of power that is available. Two-phase or 
three-phase alternating current is generally used for eleva- 
tor operation. Prior to the introduction of the two-phase 

§ 38 ELEVATORS. 47 

and three-phase systems, alternating current was very little 
used for motive purposes because the single-phase alterna- 
ting current motor would not start of its own accord under 
load ; on the other hand, two-phase and three-phase motors 
give a good starting torque and will run up to speed in much 
the same way as a direct-current motor. An alternating- 
current induction motor consists of two main parts: the 
primary, or stator, which is the stationary part, and the 
secondary, or rotor, which is the revolving part. 

The primary consists of a laminated body provided around 
its inner circumference with slots in which the primary coils 
are placed. These coils are connected together, and the ter- 
minals connect to the line when the motor is in operation. 
The secondary, or rotor, is also a laminated body provided 
with slots around its circumference in much the same way as 
a direct-current armature. In many induction motors, each 
of these slots contains a heavy copper bar, which is con- 
nected to a copper ring at each end of the armature, thus 
forming what is known as a squirrel-cage winding. In other 
types of machines, especially those that must give a good 
starting effort and are started and stopped frequently, the 
armature is provided with a three-phase winding and the three 
terminals brought out to collector rings mounted on the 
armature shaft. This is done so that resistance may be 
inserted in series with the armature windings when the 
motor is being started, and thus allow a good starting effort 
to be obtained without an excessive rush of current. In 
some cases resistance is inserted in series with the field, or 
stator, at starting instead of in series with the armature. 
This avoids the use of collector rings, but it does not give 
as good a starting effort for a given current as when the 
resistance is used in series with the armature. The student 
should note particularly that in the alternating-current 
induction motor no current is led into the armature from 
the line; in. fact, there is no connection between the arma- 
ture and the line. The armature currents are set up by the 
inductive action of the constantly shifting magnetic field 
that is set up by the two-phase or three-phase currents in the 


stationary field winding. This point should be borne in 
mind, as it will aid in understand iiig the connections to be 
described later. 

64. General Uescrlptlon. — Fig. 2H shows an Otis ele- 
vator operated by a three-phase induction motor .4. This 
motor is of the type manufactured by the General Electric 
Company and is arranged so that a resistance is inserted In 
series with the armature windings at starting. In order to 
allow the insertion of this resistance, the armature is pro- 
vided with three collector rings, shown at d, contact being 
made wilh the rings by means of carbon brushes. The 
motor operates the drum by means of a worm-gear, as 
already described in connection wilh other elevators. The 
starting, stopping, and reversing are controlled by a shipper 
sheave 5 operated from the car. When the shipper sheave 
is moved in either direction, a cam moves the rod r back 
and forth. In the figure the shipper sheave is in the neu- 
tral position, /i is the reversing switch that connects the 
motor to the line and controls the direction of rotation of 
the motor. This switch is operated by the cam f. The 
shaft s of the switch carries a number of arms, which 
engage with suitable contacts when the switch is moved to 
either the up or down position. The cam c has three prongs 
that engage with prongs on a segmental gear G, and when 
the car reaches the limit of its travel in either direction, the 
traveling nut on the drum shaft causes G to open the circuit 
and stop the motion of the car. In the position shown in 
the figure, switch R is open; when thrown to the right, it 
makes connections for the car to go up, and when thrown 
to the left, it reverses the motor. Enough backlash is given 
between the prongs of the cam c and the lugs on the wheel G 
to insure safety against overthrowing the switch. When 
switch R is operated, the motor starts up with all the resist- 
ance in the armature circuit and means must be provided for 

g 38 ELEVATORS. 49 

cutting out this resistance as the motor comes up to speed. 
This is accomplished by the controller shown at O. 

Fin. 28. 

65. The Controller. — The controller is operated by 
means of the rod r, which raises the roller^ whenever r is 
moved. The roller^ is mounted on the end of a lever, as indi- 
cated in Fig. 30 (*). Fig. 30 {a) shows a rear- view of the 
controller. D is the supporting cast-iron plate that carries 
the slate pieces S, on which are mounted a number of 



i:ontacts /„ /,, /„ /„etc. The hinged fingers/,, /,, /„/,. etc, 
also carry contact pieces, and in the position shown in the 
figure, the fingers are in connection with their respective 
contacts mounted on S. When they are in this position, all 
the resistance is cut out and the motor runs at full speed, as 
will be shown later. As soon as r. Fig. 29, is moved, roller^ 
is raised and casting /;, Fig. 30 {a), is forced down, thus 
compressing the spring /-"and raising all the fingers. At the 
same time, the reversing switch is closed and the motor 

starts up with the resistance in. When roller^ rides o 
the cam on r, the spring J-' forces up Ji, the upward motion 
being gradual because of the dashpot //. Casting Ji is pro- 
vided with a number of cams, or notches, so placed that as 
£ rises, the fingers / are closed down in pairs; i. e., the two 
lowest fingers first make connection with their contacts, 
then the next pair, and so on until all the contacts are 
closed, as shown in the figure. The closing of each of the 
pairs cuts out a section of resistance in each of two of the 
motor windings. 



66. Connections and Operation. — The operation of the 
reversing switch and controller will be understood by refer- 
ring to Pig. 31, which gives the electrical connections. 
R is the reversing switch and M the main switch, which is 
operated by hand and is only used when the motor is to be 
cut off entirely from the line. Switch R is provided with 
six clips ^ 5, 6, 4', 5', ff, which engage with the blades or 

contact arms mounted on the shaft of the switch when the 
shaft is rocked by means of tlie cam c. In the position 
shown, the switch arms engage the right-hand clips and 
connection with the left-hand row is broken. The field ter- 
minals of the motor are 7, 8, 9; and it is easily seen that 
when R is thrown over, the connections of 7 and 9 to the 

' R-l 


_■ are interchanged, thus reversing the motor. There is 
no resistance in this primary circuit, and the secondary or 
armature circuit in which the controller O is placed is entirely 
separate from the primary. In the position shown, all the 
fingers /„ /,, etc. are raised off the contacts /,, /„ this 
being the position they occupy at the moment of starting. 
The induced armature current in flowing from ring r' to r 
must take the path r'-y-l-2-S-4-r, thus passing through 
four sections of resistance. Also, in flowing from r" to r" 
it must pass through the four resistance sections /', 2', 3", 4'. 
The insertion of this resistance in the armature windings 
keeps down the rush of current through the primary and 
results in a good starting effort. As the casting £, 
Fig. 30 (rt), rises, fingers /, and contacts /, make connec- 
tion, thus short-circuiting sections 1 and i ' of the resistance. 
As E rises still farther, sections 3 and 'J' are cut out by/, 
and /, making contact, and so on, until all the fingers are 
down and all the resistance cut out. In passing from 
ring r' to r, the current now takes the path r'~/,~/^~r and 
there is no resistance in circuit. When, therefore, the fingers 
are all down, rings r, r', and r" are connected together and 
the induced armature currents are provided with a closed 
circuit in which there is no resistance other than that of 
the copper armature conductors and the connecting wires, 
67. The number of steps of resistance depends on the 
service to which the elevator is to be put. For example, 
some controllers are provided with only three sets of con- 
tact fingers, as it is found that three sections of resistance 
are sufficient to give a smooth start. The connections for 
a two-phase motor are practically the same as those shown, 
so that it is not necessary to describe them in detail. 


G8. GeDorul I^'eaturcs of Main>et Control. — In most of 

the controlling devices so far described for electric elevators, 

f out of the starting resistance is accomplished 

I arm carrying a contact that slides over a 

leans of an 

§ 38 ELEVATORS. 53 

series of plates, or contacts, connected to the sections of 
the resistance. This method works very well if the contact 
brush and contact plates are kept in good condition, but if 
either of them become rough or burned, the starting rheo- 
stat rapidly gets into very bad shape on. account of the poor 
contact and consequent burning action. This is especially 
the case if the motor requires a large current for its oper- 
ation, because the larger the current, the more perfect must 
be the connections made by the rheostat contacts, and a 
contact that is at all defective will very soon give rise to 
burning and cutting. 

69, In order to avoid the use of a sliding contact with 
its accompanying contact plates, the so-called magnet system 
of control has been devised, in which the resistance is cut 
out by a series of electromagnetic switches, each one of 
which operates independently and which is so designed 
that it will handle a large current with very little burning 
or arcing. As these switches are simply of the make-and- 
break variety and have no sliding contacts, any small amount 
of burning that may take place does not interfere with the 
operation of the controlling outfit. There are many ways 
in which the system of magnet control may be applied. The 
electromagnetic switches may be arranged to operate auto- 
matically as the motor increases in speed; they may be con- 
trolled entirely by a controlling switch on the car, or part of 
them may be controlled automatically and part from the car. 
These resistance-controlling switches, together with the 
other electromagnetic switches necessary for closing the main 
circuit and reversing the armature connections, are mounted 
on a switchboard, which is usually separate from the 
elevator motor and hoisting mechanism. 

70, Elementary System of ]VIa^net Control. — Before 
taking up an elevator with magnet control, we shall con- 
sider the elementary arrangement shown in Fig. 32. This 
diagram is intended merely to illustrate the principle and 
does not represent any special controller. It shows an ordi- 
nary shunt motor J/ with its starting resistance ^controlled 



by the two magnets S, S'. The starting and reversing 
switch is shown at A, and in this case it is supposed t' 
operated by hand. Of course, if the motor were used in con- 
nection with an elevator, switch A could be operated from' 
the shipper sheave. When the switch is in the position 
shown, the motor runs in one direction, and when it is 
thrown over so that the blades occupy the position shown by 
the dotted lines, the motor is reversed. The starting resist- 
e is divided into two sections ti, b, which are successively 

short-circuited by the electromagnetic switches 5, S' when 
the motor comes up to speed. The windings of S, S' 
are connected in series across the armature terminals, form- 
ing a shunt circuit to the armature. When the main switch 
is closed, all the resistance is in series and the pressure across 
the armature terminals and coils S, S' is very small; con- 
sequently, very little current flows through S, S'. How- 
ever, as the motor speeds up, its E. M. F. increases ai 

§38 ELEVATORS. ^ 65 

the pressure across the brushes increases, and this increases 
the current through S, S'. The armatures of these switches 
are so adjusted that S will operate with a smaller current 
than S'; consequently, as 3/ comes up to speed, S closes and 
cuts out section a of the resistance by short-circuiting it. As 
the speed increases still further, the current through Sand 5' 
becomes strong enough to operate S\ and section d is short- 
circuited, thus connecting the motor armature directly to 
the line. Suppose that the motor is to be started and that 
switches A, 5, and S' are in the positions shown. The path 
of the current through the shunt field is as follows : L-\- -b- 
1-k-l- through shunt field-/-{7-Z. The path of the main 
current through the armature and starting resistance 
is Z-h -b-l'-x-b-2-y-c- through armature of motor-^-ir-r,- 
r^S-b^-o-L, When the current through the shunt-magnet 
circuit C-S'-S-d has become strong enough to pull down 
armature a\ contact is made at z' and the main current on 
reaching z takes the path s-a'-z'-o'-r-r^-^-b^-o-L, thus flow- 
ing past section a of the resistance that is short-circuited. 
When 5' operates, the current takes the path z-a'-z'-o'-a"-z'\ 
and so on, the whole of the resistance being thus short- 
circuited. Any arcing, or burning, that may occur will 
take place at contacts z' and z'\ and this can easily be taken 
care of by providing suitable contacts. Moreover, it will be 
noticed that the closing of an armature short-circuits the 
resistance, and that when an armature opens, the circuit is 
not broken, because the current still has the alternative path 
through the resistance. The result is that when the arma- 
ture leaves its contacts there is but little sparking. 

71, When the motor is to be run in the reverse direction, 
switch A is thrown over to the position indicated by the 
dotted lines. This does not change the direction of the cur- 
rent through the shunt field, but it reverses the current 
through the armature, the path being as follows: L-\--b- 
V -x-b^"^ -n-r ^-r -d-c-y-S' -b^-o-L. Since the current 
through the armature is reversed while that in the field 
remains the same, the direction of motion is reversed. 




The scheme of using elcclromagnclic switches to control 
the starting resistance has been embodied in the controllers 
of a number of different manufacturers. It has been found.| 
that it is not necessary to provide a great many resistance 
sections and resistance-controlling switches in order to give 
a smooth start. The actual number needed depends, of 
course, on the conditions under which the motor is operated. 
With an ordinary sliding-contact rheostat, it is necessary to 
provide quite a large number of resistance sections, in ordeff] 
to keep the voltage between adjacent contact plates down" 
to the small amount necessary to avoid sparking when the 
arm slides from plate to plate. With electromagnetic 
switches the number of sections can be much smaller, 
because this precaution is not necessary. Moreover, when 
the cutting out of resistance is controlled by switches that 
are in turn controlled by the counter E. M. F. of the motor, 
the resistance is never cut out until the armature has come 
up to such a speed that it is able to take care of the increa: 
current. The resistance is, therefore, cut out just whenthi 
armature is ready for it and not before; such being the case, 
fewer resistance sections are necessary than if the cutting 
out were controlled by hand. 




73. With most high-speed passenger elevators using thia 
method, the switches that perform the same duties as Ajk 
Fig. 3'i, are operated by electromagnets or solenoids, tbuU 
doing away with the shipper sheave with its cable, cams, ; 
other switch-operating devices and replacing them by i 
electric cable connecting the car-operating switch t 

73. The car-operating switch replaces the ordinary 
operating wheel or lever used for operating by means of a 
cable. The cable running from the operating switch to the 
switchboard carries the wires that connect to the electro-J 
magnetic switches, and as these switches require only abot 
3 ampere for their operation, the wires in the controUinj 
cable do not need to be large. This method of control J 

§ 38 ELEVATORS. 57 

being used quite largely for various kinds of service, and, 
as pointed out above, it has advantages over the older 
sliding-arm method of controlling resistance. In order to 
illustrate its application in practice, we will describe two 
controllers made by the Otis Elevator Company and cov- 
ered by patents owned by them. 


74, Greneral Description of Klevator Machine. — 

Fig. 33 shows a direct-connected Otis electric elevator for 
use with magnet control. The motor ^I/operates the drum D 
by means of double worm-gears. This particular machine 
is provided with back gearing between the motor shaft and 
worm-shaft, so that unusually heavy weights, such as safes, 
may be lifted. It will be noticed that there is no electric con- 
troller connected to the machine other than the brake mag- 
net N' and the stop-motion switch M' . The brake magnet is 
a powerful solenoid that operates against the spring G^ so 
that when the magnet is energized the band brake is 
released, and when current ceases to flow through the mag- 
net, the brake at once goes on. The stop-motion switch AF 
will be described more in detail when the electrical connec- 
tions are taken up. Its function is to cut off the current 
and stop the motor whenever the car approaches the limit 
of its travel in either direction. Under ordinary running 
conditions, the intermittent gear g remains in the central 
position shown in the figure. When the car approaches the 
limit of its travel, the safety nut on the shaft of the worm- 
gear causes a pin to engage with g^ thus making it swing 
over. This operates a switch arm inside the casing M\ 
which breaks electrical connections and slows down the 
motor. When the safety nut makes another revolution, 
g is swung over another notch and the motor is stopped 
completely. The mechanical features of the hoisting 
machine are similar to those that have already been described 
and do not call for special attention. 


75. General Desc-rlptlon of Otis G. S. Maprnet Con- 
troller. — Fig. 31 is a general view of the Otis G. S. magnet I 
controller. The controlling devices are mounted on a heavy I 


slate panel j4, which is in this case supported on an ire 
framework B that also serves to house the resistance i 
With many controllers, the resistance is placed in a i 




arranged behind the switchboard. The various electromag- 
netic switches necessary for controlling the direction of 
motion of the car and the cutting out of the starting resist- 
ance are mounted on A. 

In Fig. 34, S' is the potential switch, the use of which 
has already been explained. It is a protective device and 
is not concerned with the regular starting and stopping of 
the elevator. When the elevator is in operation it remains 
closed. Switches C\ D' , and li' control the main current. 


Switch //■ controls the brake and the two groups of 
switches^' and F' control the resistance. The group of 
four switches F' controls the starting resistance and the 
pair of switches G' c<mtrols the stopping resistance. With 
these contmllers the motor is stop|)»;d by allowing it to act 
as a generator, thus providing a dynamic-braking action in 
addition to that of tlie band brake. In order to allow a 
snuHith braking action, the current generated by the motor 
is p,-tsseil through a resistance, and this resistance is cut out 
or in by magnets G '. The main operating magnets f"', //, 
and /:" are of the solenoid type, and when they are not 
excited the |4ungers are down and the upper switch con- 
tacts, as c, fur example, are separated from the fixed con- 
tacts (/. The movable contacts c are mounted on rocker- 
arms a. It' pivoitd as shown at ^. The plungers of the two 
switches />' and F' are connected by a lever/, as shown, so 
that when one contact lever a is up, i. e., the upper termi- 
nals in cimtact, the other lever «' is down, and it is irajjos- 
silile f>>r both levers to iKcupy the up or down pfisition at 
the s:imc time. The operation of these switches will be 
understood more clearly by referring to Fig. .to (it). 
Switches /'" and (/ are arranged as shown in (d) and // i^ a^ shown in (<). These sketches are intended 
nirrrly lo iiidi.;itr tin: ojn-ration of the switches, so that the 
di.i:.^iMni "i .'.(iiiifii.iDs to be given later may be readily 
iiii.l.T-i'H'd ; hi-nrr, iJarticiihir attention has not been paid 
i.i -Ji.- HI. lb, mil-, il .li-uiiN. In (if), when the magnet dnrws 
i;j> ;h.- plLin--r, li \rr ,/ i-; tiMved so that f and i/ make C 

■..■■i.-^^mI i,„f,, .,11,1 ,/■ are. of course, opened. Coi>-.| 

;.L-'.- ■', ■■ .111' -i.qiditc blocks mounted on spring holdoi 
■'■','■ 1 "t il'.i' .Lir.ijihitc being to prevent damage j 
■:■ :::i'^ < >i -|mi I. kil;. ;i:iiI especially to obviate the il^gfff C 
i~ oi sticking, ta|uyH|Mh«iuhl pWBJblr 




series of cores //, opposite each of which is hinged the arma- 
ture a carrying an insulated contact ^, which makes contact 
with d when the armature is drawn down. When current 
flows around coil f, all the cores are magnetized to about 
the same degree, but the armatures are not all attracted 
because they are adjusted to different distances from the 
pole pieces s by means of adjusting screws / that rest 
against lugsr. The armature with the shortest air gap 
between a and s is first attracted, then the next, and so on, 
the armatures closing in succession as the magnet increases 
in strength on account of the motor speeding up. The 
resistance is thus automatically cut out by steps, as explained 
in connection with Fig. 32. 

Fig. 35 (c) shows the switch indicated by //' in Fig. 34. 
It is practically the same as (^), except that it is provided 

(h) (0) 

Fig. 35. 

with two insulated back contacts /', ;//' to which the 
leads / /// are connected. When armature a is unattracted, 
/' and m' are in contact; when a is attracted, contact 
between /' and ;//' is broken and contact between c and </ is 
closed. The switch contacts that are most liable to arcing 
are provided with magnetic blow-out coils. These are coils 
provided with an iron core so placed that a magnetic field 
is set up between the contacts, and as soon as the arc forms, it 
is forced across the field and broken almost instantaneously. 

H. S. V.—J9 




;<;. Cui'-UiK-mllriK hwlU'li. -Fiy, .Hi shows llic style of 

car -ope rating switch used with the magnet cuntroller. When 
the moUir in stopped, the handle occupies the vertical posi- 
tion ami is thrown to the left or right, according as the car 
is to go up or down. When the cover is closed ami the 
switch in use, sliding contacts c. r bear against the arcs a, rt. 
h, f>\ when the switch is off, they bear against the insulating 
pieces il, il. The contacts on ihe back of the operating 
lever press against segments c, thus making the required 
connection. Ilv adopting the construction shown, no cur- 
rent flows through [he hin^e/. The exact arrangement of 
the contact segments 
varies with different 
controllers, as the 
starting and running 
requirements are not 
always the same 
for different installa- 
tions. The opera- 
tinii switch for which 
Liie connections are 
in Fig, 38 
i^ somewhat simpler 
than that shown 
ill Fig. .'Jfi, and re- 
fewer wires 
. contact arcs, but 
general construe- 
1 IS [hi samt. 


ready bi 

F^ I op- Moth 


Lwo views 
sti i|> motion 
,how n at M\ 
The use of 
itih has al- 

ihc ionsiructi4H 

I' 98 



will aid in undcrstfindiiig the electrical connections. 
The arm a, which is <iperated hy the intermittent seg- 
mental gear .5-. normally occupies the horizontal position, 
but is swung around whenever the car reaches the limit of 

iits travel. Contact brushes are mounted on the arm, and 
these rub on the contact arcs i, b. When the arm is swung 

around in either direction, one svt of brushes leaves the 
long contacts h, b and passes on to the short pieces c, r. 
Arcs r, c are, with the controller to be described, not con- 
nected to anything, but serve as bearing pieces; as soon, 
itherefore, as the contact arm slides on to them, electrical 
connections are broken, which causes the motor to stop. 

78. Connections fbr G. H. Controller. — Fig. 38 shows 
the general scheme of connections for the G. S. controller. 
[a order to simplify the diagram, the relative positions of a 
few of the parts have been changed ; for example, the start- 
ing resistance and the extra-field resistance r r' are shown 

mnected directly to their switch contacts. The relation of 
'the various switches is the same as shown in Fig. 34, except 
that their order is reversed, because all the connections are 
dade on the back of the board; corresponding switches in 
IFigs. 34 and 38 are lettered alike. In order to facilitate 
(he tracing nut of connections, all fixid contact pieces on 
the switches have been shaded, while all movable pieces have 
been left open. For example, on switch /:'' the shaded con- 
tact pieces &' , «', 7', and fl" are mounted on the slate panel 



and the open contacts 5, 6, 7, and 8 are mounted on the 
tilting arm shown in Fig. 35 (^i). Also, contacts that toudi 
each other are marked with similar figures, i. e., when 
switch £' is pushed up, S makes contact with 5' and 6 with 6*. 
A few details, such as blow-out coils, have been omitted, as 
they are not necessary to illustrate the operation of the con- 
troller. The car-operating switch controls switches £\ /?*, C, 
and //'; switches Af\ F, and G' operate automatically. 
The main switches E* and H are each provided with two 
coils. One of these coils is of fine wire, and the current in 
it is controlled by the car-operating switch. The lower coils 
are of coarse wire, and carry the main motor current ; these 
coils are arranged below the fine-wire coils and, when 
energized, hold the switch down. When switch C oper- 
ates, 13 makes contact with i^', H with H\ and contact 
between 15 and Iff is brokcjn. When H' operates, contact 
is made between IG ^i^A 1& and broken between 17 and IT, 
When switches G' and*/^' operate, contact i? made between 1 
and I'y 2 and ^^ etc. SThe movable contact pieces of the 
stop-motion switch M' bccUpythe horizontal position shown 
until the car reaches the limit of its travel in either direc- 
tion. The full-black segments on this switch are not con- 
nected to anything, being in this case bearing surfaces 
only. Switch P' is provided with a pair of contacts on each 
side of the **off" position. Two contacts u* and if are 
longer than the others/"// and/"^/, so that the lever makes 
contact with the former before the latter. To avoid confu- 
sion, a wire is shown connected to the lever instead of 
( arrving the current to it through sliding contacts, as is 
(lone on the switch shown in Fig. 30. An additional safety 
swiuh .V is sometimes provided to stop the elevator in 
cnuTi^cncics, but it is not in use under normal conditions. 

71>. lypo of Motor Used Willi G. 8. Controller. 

Ik'forc lakini^ up the action of the controller, it will be well 
to consider briefly the type of motor used with this system 
(.t (oiurol. In order to j^et the elevator imder way quickly, 
it is necessary that the motor should give a strong starting 



(.,. ; •■■ 5?w YORK ■ 

i=- - juc ubrary! 

§38 ELEVATORS. 65 

torque. This is provided for by the series field. The shunt 
field furnishes the excitation after the motor has attained 
its speed. In addition to these two windings, a third, or 
extra-field, winding is provided. This winding aids in pro- 
viding a field when the motor is being brought to a stop, by 
allowing it to act as a dynamo; it also aids to some extent in 
providing a strong field at starting. It should be remem- 
bered that a shunt-wound motor will run as a generator if 
it is disconnected from the mains when up to speed and a 
path provided between the brushes for it to send a current 
through ; it is not necessary to reverse either field or arma- 
ture connections in order to make it generate, as is the case 
with a series motor. 

80. Operation of Controller on First Point. — Sup- 
pose that the car is to. be run up and that che lever of P' 
is moved to the left until the arm comes in contact with the 
long arc u\ but does* not touch the contact f it. The oper- 
ating current then fiows as follows, starting from point IS 
on the -j- side of the potential switch: 18^ through coil of 
switch //', through coil'of the **up" magnet D\ through 
wire // // to stop-motion switch M\ to contact strip //', by 
way of the horizontal strip, through flexible car-operating 
cable to contact //' on car-operating switch, through lever 
to w^ thence through safety switch and wire y y y to the 
negative side of the potential switch. This current oper- 
ates switches D' and H'. Switch D' is drawn up by the 
fine-wire coil and contact is made between 9, 0' and JO, 10\ 
as indicated by the dotted lines. This allows current lo 
flow through the shunt field by way of the path -| — 18-0'-9-D- 
through shunt field- //-1 9-20. The operation of //' releases 
the brake by connecting points J6 and J6\ because point I) 
connects through Z>' to the -f- side of the circuit, and 
when 16 and 16' are in contact, the other terminal of the 
brake magnet connects to the negative side of the circuit. 
This releases the brake and allows the motor to start as 
soon as current flows through the armature. When 
switch N' operates, points i7, 17' are separated so that 




no current can flow through coil /■, and, hence, switches C 
are open so long as the motor is working. As soon as 
switch D* is forced up« switch E' makes contact between 
7, 7' and **?, cV, because of the connecting lever i. Fig. 6. 
The main current then takes the path indicated by the 
arrowheads as follows: l^-0\ 10'-9^ i(>-^^-/-th rough arma- 
ture of motor to ^i-through series coil of switch E*-T^7-H- 
//'-6''-J'-;?'-4*-through whole of starting resistance to F- 
through whole of series field to H''19~20 to negative side of 
the circuit. The current through the series coil of E' 
holds the switch arm down firmly. The motor, therefore, 
starts up with the two sections of the series field and all 
the starting resistance in series with the armature. The 
extra field is in series with the resistance r r', and the two 
together are in shunt with the armature. This is easily 
seen by tracing the path through the series field, beginning 
at point A as follows: Z>-through extra field-^'--Jr-r -r- 

Fig. 39 represents, diagrammatically, the connections 
that are made on the first position of the switch P\ The 

STstftnmt 4Gr<£ 




xsomoomm^ = 

Shunt f/eio 

V\K.. ;)«.). 

extra firld docs not supply nearly as much magnetizing 
power at start iiii^ as when the motor is stopping, because, 
at stariinLi, the i)ressure across the armature terminals is 
small. ^ Ml this point of the controller, therefore, the motor 
starts up, but would run the elevator at a slow speed because 
of the resistance' in circuit. It should be noted, that as 
lon^ as the ()[)eratinj2: handle rests on //' or d\ the resistance 
swiiehcs /-' are inoperative, because one terminal of coil A 
connects to e(»ntaet /•> <>n switch C\ which is open. 

§ 38 ELEVATORS. (it 

81. Operation on ** Faist Tp'^ Position. — When the 
handle of P' is moved over farther, so as to make contact 
with the f u (fast up) contact, current flows through the 
solenoid of switch C\ thus forcing the switch lever up and 
making contact between yj, IS' and /^, 7^'. At the same 
time contact is broken between A7 and ir)\ thus opening the 
circuit through the extra field, which is now no longer 
needed, as the motor is by this time well under way. The 
operation of this switch allows current to flow through the 
magnet coil // and resistance x\ as indicated by the dotted 
arrows, beginning at point ,U. This operates the group of 
switches F\ First 2 and ^i' are connected, thus cutting out 
the first section of resistance, then S^ S\ cutting out the sec- 
ond section, then 6", G\ cutting out what is left of the 
resistance and also one half of the series field; finally, 
//and //' are connected, thus cutting out the other half of 
the series field. The motor has now attained its maximum 
speed, and the path of the main current is -| — JS-ff\ lO'-O, 
lUSS'-I-xhrongh armature-/r-7'-r- ///-// '-//-//' to nega- 
tive side of circuit. The motor now operates as a plain 
shunt machine with no resistance in circuit. 

82. If the operating switch were moved in the reverse 
direction, switch /:' woilld be moved up and switch // would 
be down, as can be readily seen by tracing the connections. 
The main current then takes the j)ath lS-fj\ o'-O, Ct-l^-Lt- 
through series coil of />'-/:-th rough armature-/-/7'-y/-/^, 
and so on as before. The current in the armature flows in 
the reverse direction to what it did before, while the cur- 
rent in the fields remains unchanged; the car, therefore, 
moves down. 

83. Action of Controller on Slo^vinfl: DoAvn and 
Stopping:. — Suppose that the elevator is running on the 
** fast up" point and lliat the handle is moved back until 
it leaves contact /' //, hut still rests on contact //'. Switch C 
will be opened, and this will cause switches /'' to open, thus 
cutting the resistance and series field bac^k into the circuit; 
the extra field will also be connected, because 1'} and /J' will 



make contact, the resistance r r' lieiny in scries with the 
fxtra field. Quite a large current will now flow through 
the extra field because the potential across the armature is 
hiyh. When, therefore, the handle is moved back from the 
fast position, the field of the motor is greatly strengthened 
and all the resistance is cut back into circuit, thus rapidly 
lowering the speed of the motor. On account of the 
decrease in speed and the cutting in of the resistance, the 
pressure across the brushes is considerably decreased when 
the handle is moved from the fast position. When the 
operating handle Is moved to the off position, switches 
D' and // ' are opened. D' breaks connection with the line, 
and //' sets the brake by separating points J6, 16' and 
opening the circuit through the brake magnet. At the 
same lime, points 77. IT are brought into contact, thus 
connecting coil k across the armature terminals. The 
pressure across the armature terminals is large enough to 
cause switches Ji, 4' and /, 1' to close, thus cutting out r' r 
and connecting the extra field across the armature. The 
armature thus generates current, which takes the path 
/-if -8- D' -extra. lield-K'-i-4'-!4-7-7'-E. The current 
through the extra field remains in the same direction as it 
did when the motor was run from the line and hence assists 
in keeping the field magnetized and bringing the motor to a 
stop quicker than if the .shunt field only were used. As the 
motor slows down, the magnetization supplied from the ) 
shunt-field coil diminislies; hence, the provision of the extra i 
field supplied with the current that the motor furnishes | 
when running as a generator greatly increases the braking 
action. The generating action soon slows the motor down, 
and as the pressure across the armature terminals decreases, 
switches 4> 4' and 7, /' open in succession, because A" is no 
longer able to hold them. This cuts resistances r', r back 
into circuit with the series field, thus making a smooth 
slop and leaving the resistances r, r' in series with the extra 
field ready for the next start. Of course, while this action 
is taking place, the band brake is also on because the ■ 
dynamo-braking action decreases as the speed decreases, 

§ 38 ELEVATORS. 09 

and hence would not answer, in itself, for bringinjj^ the 
motor to a full stop. All these actions take place in a 
very short space of time, but the effect is to stop the motor 
smoothly and quickly, and the car is at all times easily con- 
trolled by switch P\ the cutting out of the resistance and 
the connections necessary to produce the dynamo-braking 
action being made automatically. 

84. The stop-motion switch J/' merely brings about 
automatically the same connections that P' should, in case 
the operator failed to move P' when the car reaches the 
limit of its travel. When the contact arm is swung around 
by the action of the traveling nut, as already explained, 
contact is first broken, if the car is ascending, between the 
/"//and /"contact arcs, thus slowing down the motor; and 
as the car travels still farther, contact is broken between 
arcs u and //', thus applying the brake and stopping the car. 


85. General Description of No. O Controller. — 

Fig. 4rO shows the general arrangement of the Otis No. G 
magnet controller. This is a later type than the G. S. con- 
troller previously described, and although its mechanical 
details are quite different, its principle of operation is 
almost identical. The resistance, which is usually in the 
form of cast-iron grids for controllers of large capacity, is 
arranged behind the board and does not appear in the figure. 
The various switches are marked A\ />', C\ /, 2, J, ^, />. 
Switches A\ B\ C\ and 1 are operated by the car-control- 
ling switch; the other switches operate automatically. 
Whenever a switch, for example 6 ', operates, its plunger e 
is drawn up, thus bringing the copper disks li, d' up against 
the contact fingers/*, f. When a switch is deenergized, its 
plunger drops and the disks make contact with the lower 
fingers where any are provided. When a disk is drawn up, 
it first makes contact with the auxiliary carbon contacts .r, 
and as it is pulled up still farther, it bears against a copper 

Cf Atact oo a finger Inngnl at the same point as the finger 
that carries the carlHin nnntacl. When a disk ilmps. it first; 
breaks contact at the iiipjwr surfaces. antJ iIr- final break. 

itveen the ctijiper and ilie carbon terminal, sofl 
("no danger of slickiny. The carbon pieces are 
r as to pri'vent iheir wnrkiny; tuosc and slidinj 

^^hrough the holders, Thi^ iiliingcrs with their contact 
plates are free tn revolve, and the motion of the switch 
gradually works them aronnd so that whatever burning 
takes place is spread around the whole disk instead of in 
one place only. Switches S, 3, i. and fl operate automat- 
ically, one after the other, and the voltage at which they 
operate is adjusted partly by regulating the initial position 
of the plunger by means of the adjustable stops //. and 
tartly by inserting a resistance in series with each solenoid. 
main fuses are shown at /■, ^; they are of the enclosed 
ype. The small knife switches shown at f are used for cut- 
ing off the car-controlling switch, so that the motor cannut 
e started from the car. Push buttons/ u and fi if are used 
I allow the motor to be operated from the board. These 
jviccs are very useful when tests are being made to locate 
■ouble. but under ordi- 
lary working conditions 
Jiey are not in iise. 
iwitches A' and H' con- 
Tol the direction of mo- 
ion of the car. When A' 
•perates, the car descends, 
ind when B' operates, it 
K^ends, Switch C closes 
ind opens the main circuit. 

86. No. Car-Con- I 
rolling Switch.— Fig. il 
lows the car-controlling 
vitch used with the 
lO. 6 controller, the cover 
sing removed in order 
> show the working 
arts. The operating han- 
le is shown at h, and 
normally occupies the 
intra], or off. [Kisiiion. 
Then moved to the left, the car ascends, and when moved 


• V 


t» the right, it descends. The arm carries a contact arc b 
that makes o:«ntact with the fingers 7, ^, J, -f, etc. when the 
handle is moved from its central position. The arc 6 is of 
su«:h a length that when the handle is moved to its extreme 
position in either direction, it makes contact with all four 
lingers on the side to which it is moved. The handle A is 
held at the central position by means of a spiral spring j, so 
that if the operator releases the handle, it at once returns to 
the off position. When the handle is at the off position, the 
projecting rim k rests in a notch in the plate /, and in order 
to move the handle, it must first be pulled out against the 
action of a spring. Insulating pieces i are inserted between 
the fingers, as shown, in order to avoid short-circuiting. 

87. Connections for Xo. 6 Magnet Controller. — 

Fig. 42 shows the connections of the No. 6 controller. In 
this diagram the positions of the switches, resistances, and 
motor armature and field windings have been arranged so 
as t«> make the diagram simpler and easier to follow than if 
the various parts were located in the same positions that 
they occupy on the controller. The connections are, how- 
ever, the same as used on the controller shown in Fig. 40, 
and corresponding switches are lettered alike. The oper- 
ation is on tlie whole verv similar to that of the G. S. con- 
trailer. Terminal x of the operating circuit is connected 
to the -j- line and terminal r to the — line. By throwing 
the small switch c down into the dotted position c'\ the car 
( annot be operated from /^'. Switch ;// is normally open, 
bill it can l)e thrown so as to connect / and d or t and n. 
It" i is thrown down to the positions" and ;// is thrown down 
so as to connect / and d, magnet A' is energized, and if 
push button /><'/ is then pressed, current will flow through 
the coil of C and the elevator will move down. If ;;/ be 
thrown \\\) so as to connect ;// and u and button/// pressed, 
switches Ji' and C will be operated and the car will move 
up. In other worcls, the small switches and push buttons 
allow the machine to be operated from the controller while 
the switch P' is cut off. 




1;.)' -'-U' >'0l>7"""' 



§ 38 ELEVATORS. 73 

88. Operation of Xo. 6 Mtn^iiet Controller on Start- 
ing: Position. — Assume that the operating handle is moved 
to the left so as to bring the arc s in contact with ;/. Start- 
ing from Xy the path of the operating current will be as 
indicated by the arrows through the coil of />' to the nega- 
tive terminal y. Note that this current passes through the 
small contacts 1 and Si of switch A\ so that unless switch A' 
is down, /?' cannot be drawn up, and it is impossible, there- 
fore, for both switches to be drawn up together. When c is 
moved still farther so as to bring it in contact with the ^n- 
ger /;/, a current is set up through the operating circuit, 
which includes the solenoid of switch C This current may 
be traced as follows: x-c-c'-p u-p u to contact / // on stop- 
motion switch-/-P-th rough solenoid of ^-^-.7-^—7 to line. 
This current operates C\ which closes the main circuit, 
releases the brake, and connects the shunt field and extra 
field across the armature. The various paths of the current 
are indicated by the arrows, bearing in mind that />" and C 
are now up. A powerful magnetic field is provided by the 
series coils, and as the motor comes up to speed, switches ^ 
J, ^, and 5 operate, thus short-circuiting the resistance and 
the series field. For example, when switch 2 closes, the 
main current passes from terminal R,^ to A',, thus short- 
circuiting the first two resistance sections. When the 
handle of P is advanced so that :: makes contact with fin- 
ger /"w, switch No. 1 is operated. This breaks connection 
between R^ and J/, thus cutting out the extra field. The 
switches are now all up except A' and the motor runs with 
a shunt field only; the resistance is all cut r^ut and the 
motor runs at its maximum speed. When C is up and when 
switch 2 operates, contact is broken between the small ter- 
minals S and Jf^ so that the current through C has to take 
the path through the resistance r^, to the negative side of the 
circuit. This resistance is inserted to prevent undue heat- 
ing of C and also to save current. Also, when switch J is 
operated, the current throujj^h the coils of ? and J is cut off, 
thus preventing these coils from heating and cutting off the 
current necessary to energize them. When the core of J 

74 ELEVATORS. § 38 

drops, contact is established again between points S and -J, 
but in the meantime it has been broken between 5 and 6 so 
that the current through C still flows through the resist- 
ance Tp. The coils of /, 4^ ^"^ '^ have considerable resist- 
ance in series with them and do not overheat. It is, of 
course, necessary that these three should remain up while 
the motor is running, otherwise the extra field resistance, 
and series fields would not be cut out, while with switches 2 
and 3 it is not necessary that they should remain up after 
sections 2 and J of the resistance have been cut out. The 
voltage at which switches 2, J, 4» and o operate is adjusted 
by means of the resistances r„ r^, r^, switch 2 having no 
resistance and, therefore, operating at the lowest voltage. 
When F is moved to the right, switch A' is energized and 
the elevator descends because the direction of the current 
through the armature is reversed, while that in the fields 
remains the same as before. The action of the stop-motion 
switch is the same as in connection with the G. S. controller 
and needs no special description. 

89. Opeiiitioii of Xo. (> Controller on 8toppin|i:. — 

When P' is moved back, contact is first broken with the 
fji finger. This drops switch / and cuts one section of 
resistance into circuit as well as connecting points ^^and M, 
thus cutting in the extra field. When cimtact is broken 
with finger///, all the resistance is cnit in and the main cir- 
cuit is opened because switch ( ' is dropped. In fact, the 
switches ?, -A J, and J will likely operate before contact is 
actually broken i)clwcen .z and /> //, if the operating switch 
is not moved loo (juickly, ixM-ause the cutting in of the tirst 
section of tlie resistance and the extra field will lower the 
speed and thus cut down the E. M. F. apj)lied to coils 2, .;/, 
.}, and '7. When C dro[)s, the brake is applied because the 
circuit through th(» i)rake magnet is opened. When the 
main circuit is oj)entMl l)y C\ tiic armature is still able to 
send a current around ihc loeal eircniit /:'-.V, -through stop- 
])iii^ ii'sistanee - /^ t hrougli extra fudd and extra-field resist- 
ance- J/- A'^-A^^^-Yv,-/, because switch B' has not yet dropped. 


This jrenerating action throujrh the series field, together 

W'ith the brake, will soon stop the motor, even if /^ is not 

^oved to the vertical position and connection broken with 

^Hjrer //. The car can, therefore, be stopped without the 

'^•'oessity of oi>eratinf^ the direction-controlling switch. For 

^->^5iinple, if the elevator were making an up trip, stopping 

^^^ vach floor, the handle would be moved far enough to 

^*''t_'ak contact with/// only, and />" would remain up during 

^''i^ whole trip. When /^ is moved to the off position, 

i^W'itch B' drops and the stopping resistance is connected 

^■^i"cctly across the armature terminals. 


SK), Goiiei-al Description. — An automatic elevator is 

^**^t-» that does not require a regular operator, but is so 

^^1" ranged that it can be controlled by the passenger. These 

*^K*vators are largely used in private dwellings where the 

^Wvator is not used very frequently, and where it would not 

* *t.' desirable or convenient to have an elevator boy. 

Dl, Automatic electric elevators are, with the e.xception 
*>f the controlling devices, similar to other direct-connected 
<^lectric elevators. There are a number of different stvles 
('f them, but the general method of tiperation is about as 
follows: A push button is provided at each landing, and in 
the car there are as many push buttons as there are floors. 
A passenger at the third floor wishes, say, to go to the first 
fl(H)r. He presses the button at the third floor and the 
elevator comes up or down, depending on what location it 
inav be in at the time, and when it reaehcs the third floor it 
stops automatically, at the same tiinr mil' k king the door. 
The passenger then gels in the car, closes the door of the 
elevator shaft, and presses the firsl-flonr push i)iitlon in the 
car. The car then descends uni 11 it reaches the first flo<^r and 
stops thereof itsownae<'ord. In tlK-aulonialic elevator made 
hv the Otis Companv, llic variuus devices are so arranired 
tliat when the elevator is nncL' started i>y the passenger 

76 ELEVATORS. § 38 

it cannot be interfered with by any other person. Also, it 
is not necessary that the push buttons should remain closed 
while the elevator is in motion. All that is necessary is to 
press the button for an instant and then release it. Various 
safety devices are also introduced; for example, it is impos- 
sible to operate the elevator if any of the doors of the shaft 
arc open, and no person on any of the floors can possibly start 
the elevator if anybody at any of the other floors is getting 
on or off. We will describe two types of Otis elevator 
provided with automatic control, and these will serve to 
illustrate the principle of automatic control in general. 
The two types are practically the same with the exception 
of the automatic floor controller, which is geared to the 
elevator drum. 


92. General Description. — Fig. 43 show^s an Otis auto- 
matic electric hoisting machine provided with their older 
type of floor controller. In general appearance it will be 
noted that the machine is much the same as those previously 
dcscrii>c(l in connection with magnet control. About the 
onlv difference is the addition of the floor controller shown 
at (\ A spiral contact band a is mounted on an insulating 
drum, whicli is moved sidewise by a coarse screw as it 
revolves, so that the contacts /; always press against the band. 
The various contacts /; connect to the push buttons at the 
different floors. The controller C is used to determine the 
direction of motion of the car when any given button is 
pressed, and also to stop the car when it reaches its destina- 
ti<)n; its action will i)e understood when the electrical con- 
nections are described. The strip /> is arranged in spiral 
form on the drum simply to avoid the use of a drum of 
lar<>e diameter. 

{)•{. Ma^iu^l Controller for Automatic Elevator. — 

Vii^. 14 sliows ilie magnet eoni roller used with the automatic 
ilevatwr. ./' is tiie main switch that controls the direction 
of rotation of the motor. A swinging armature x is hung as 

g 38 ELEVATORS. 77 

shown, between the poles o£ the two ironclad magnets j, «'. 
When it hangs in the central position, the circuit is open. 
When a button is pressed, one or the other of the magnets 
is excited, depending on the direction in which the car is to 
move. The armature is drawn over and contact established 
between the swinging terminals y attached to the arma- 

ture and the fixed terminals i,'. The pair of magnets C 
outs out the starting resistance, and magnet B' rinses 
the main circuit and releases the brake. The devices 
shown at d, e, f, g. Ii, and k are known as floor inR(cii<>ts, 
and their function is to hold the pusJi-button circuit closed 

H. S. V.—ZQ 

after it has brvn nnce prv&icij. «vcn tboogli tbe opcraior4 
releases the push buttonitself; their action will bcriplai 

Uler. Magnets /. ii 
are provided ti> pre 
rent interference ' 
with tbe elevatciT 
from other floors 
until tbe party whii 
is alrcadr operating 
it is thr^tugh. 

94. C a n u e e - 
1 1 o Q s tor Auto* J 
matic Klerwlor.- 

Fig. 15 shows a dta-l 
gram of L-onnectionfl 
for an Otis auto- 
matic elevator i 
the style •>( 
controller shown iqf 

»».«. ''* "■ ^''" 

preceding dtagrams^l 
tbe location of some of the parts has been changed lam 
order to make the connections easy to follow. The diiii 
gram shows the connections necessary for the control i 
the elevator from four floors. --I' is the reversing switchjj] 
the open contacts are mounted on the swinging armatui 
and the shaded contacts are fixed. When coil s ts excilei 
the armature h drawn towards s, and the open loniaci 
make ci.nncction with the lower row nf fixed omtacts, g 
indicated by the doited lines. We will assume that ' 
the connections shown, the car moves up when roil 
energized and down when / is energined. Switch />" cioj 
the main circuit; 1",S",S'. i" arc the small floor magnet! 
shown at </. c, /. etc.. Fig. 44; 1, ,*. J.4 arc the push buM 
tons iin each flwjt: J', ■J', S' . i' arc liic push buttons on tb 
«levalor; f/,, (/,, i/,. rf, arc dcmr lontacls. These contacts ari 
ID Series and are connected together as shown only wheD(| 

*' . 

^^ Lj.. 

-f U " N i *" ■' ■ 



1. _ 


all the doors of the shaft are closed. If any one of these 
contacts is open, i. e., if any door is not closed, it is impos- 
sible to start the elevator. The two switches for cutting 
out the resistance and the series-field coils are shown at c\ 
and they are operated by magnet ///'. C is the floor controller 
driven from the winding drum. The two segments ^, a' 
represent the strips a shown in Fig. 43. On the drum itself 
they are put on spirally in order to allow a small diameter of 
drum, but here they are shown as two arcs, so that the con- 
nections may be more easily followed. With the position of 
the controller shown, the car is at the bottom of the shaft, 
i. e., at the first floor. As the car ascends, the controller 
turns as indicated by the full-line arrow, and a' slides from 
under ^^2\ 3S\ 44' y and //' in succession. At the same time, 
segment a comes in contact with 11', 22\ 3S\ and 44' in 

95. When switch A' is pulled by coil /, contact is broken 
between the auxiliary contacts 12]^ 1^\ thus opening the cir- 
cuit through coil J. Also, when ^1' is operated by coil s, 
contact is broken between contacts l-h 13\ thus opening the 
circuit through coil /. It is, therefore, impossible for both 
s and / to be excited at the same time. When switch c' 
makes contact at /^,, contact is broken between 14 and 14' ; 
when contact is made at A',, contact is broken between 
lo and 15'. When the armature of magnet ;// ///, is drawn 
up, contact is broken between points />, '>' ; when the arma- 
ture of / is attracted, contact is made between points 
10, 10*. When magnets /", 2", J", etc. operate, contact is 
made between S and -5', 6' and ()\ etc. When buttons 
r, 2', 3\ or 4' are pressed, contact is made between wire c 
and the wire running to the floor magnet corresponding to 
the button that has been i)ressed. 

96. Operation of Aiitoiuatif Klevator. — As already 
stated, the controller 6' indicates that the elevator is at the 
first floor. Finger //' is open-circuited, and, pressing either 

jr button / or 1' would not start the elevator, because it is 
already at the first floor. Suppose a passenger wishes to get 



or. d: the thiri r. -rrar.! then go down to the first floor. He 
pre>2^> the th:ri-n> r butt«:.n -J. and the elevator moves up 
t ;* the t'r r.: r. ^. r ar.c st :d> there, at the same time automatic- 
ally url •:k:n^ the i-.r v-t the shaft. After the passenger 
'/Ids e-terc : the clrvdt r and cl«>sed the door, he presses 
b;:tt- n .' :r. thr car ar.i the elevator descends to the first 
rl>r an.: st : >. The way in which the control is brought 
aSiit will Ve>t>x: by following the circuits in Fig. 45. 

07. When'.^n •_> is pressed, the operating current, 
start i!:^: fr :n > int J v-n the main -*- ^ire flows through 
the slack oaVlr switch. thr«»ugh d<H;>r contacts d^-d^-d^-d^^ 
ihrouvjh caMe t • car and thp'ujih safety button on car \o A- 
. t-. ^-v. -•:-:• -:*-:^-:+-;^-/'»-/.'^ through push button SS^ 
thr.'u^h ri«vr nia^inet * — i-w >.i-finger ^/-strip ^I'-finger 
:i -:i-;*-mav;net y- ;,-.',* . through I' L magnet of B\ through 
limit switch «^n machine, through limit switches at bottom 
ot shaft. t«^ neirativtr side "f the circuit at j. This operating 
current accomplishes several results. In the first place, it 
closes magTiet ■* so that contacts d and & are brought 
iMvrether. T::is provides a path for the operating current 
that is iiuic'.H-ndent i»t the p>ath through push button S. 
The cnrre::: car: :.«'W r!- \v al-'ni;: A A through coil fH-r-(>-6' 
thr«»i:^:i c^-il • . arid > • n as !'ef«»re. Consequently, after":: ■•' * ^ r". :»';es>t«.l :iu- car will start up, even though 
■ I'c rr!fa>t d. .i^a::.. a*: : i: :< rv-t necessary for the passenger 
t ' k. r:i li.c ': lit: •:i ;rv><c'.: in.::! the car reaches its destina- 
i" :.. A!! :l\ii :> :.:. vssary i-* t'» press 3 long enough to 
.1." "A • : ..••.:\i I •:< ..r:::.i:r.rt-. When the of)erating cur- 
r- M *./< - •. :'A\\\ :*;.r ...;!: ''—'', a resistance r, is in circuit, 
:- ' y .L -:-... . ■;.( i\.: : _: k ;:rrc:.t is r.ceded to hold the arma- 
i::- a'::- .:. y ■..i\v con a::rac:od. The operating cur- 
T' :;: :". v.- •".'■ .••.^■■: .^- ..::.! ,.r.c c.»il ■ -i switch />'. Hence, the 
i«\ '•••-::;;: -■•.'.::■:: > :)■;!;<•. 1 to I'hc up position and the main 
< ir- -.ii :^ < !■.-•!. :':::- a!;.»winv^ the main current to flow as 
ii:'!:- a:'.'! ly i:m.- arr'-us and startinj^ up the motor. The 
np.-rat :: l:" ..f iij«— • >wi:clu-s al>«» allows current to flow 
t}ir<>:iL;ii lii'- ^iiuni-rir/id cmjI and brake solenoid, thus releasing 

§ 38 ELEVATORS. 81 

the brake. When coils /;/, w, are energized, points /?, 9' are 
separated, thus breaking all connection between wire A A 
and wire 17, 18, 19, which leads to one side of all the floor 
buttons; consequently, as soon as one button, in this case 3, 
has been pressed, the buttons on all the other floors are 
cut out of service, and it is impossible for any other 
parties to operate the elevator. As the motor speeds up, 
switch R^ operates because coil ///' is connected across the 
armature terminals, and this cuts out the greater part of 
the resistance, at the same time separating points 14, H! , 
When sufficient speed is attained, switch R^ operates and 
cuts out the remainder of the resistance and the series field, 
at the same time separating points W, 15'. 

98. All the time that the car is going up from the first 
floor to the third, controller C is turning as indicated by the 
arrow, imtil, when the third floor is reached, a' slides from 
under finger 33', thus interrupting the operating current and 
stopping the motor. The motor is stopped by the band brake 
and no provision is made for a dynamic braking action, 
as these elevators are not intended for high-speed service. 

©9. After the car has stopped at the third floor and 
automatically unlocked the shaft door, the passenger slides 
back the door, thus opening the operating circuit at con- 
tacts d^ and making it impossible for any persons on the 
other floors to start up the elevator while he is getting 
on. After closing the door and thus reestablishing contact 
at rf,, he presses button i'. This allows the operating cur- 
rent to flow as follows, starting from y as before: ^-slack 
cable ^^-d-d-d^^ through cable to safety button on 
car-^ -/I -^1 -through m -1-15' -lo-c-c^^-l' -1-1 ^1-1 V'-ll- 
ll-ll'-a-^'-D-t-13-lS'-D L, through limit switch on ma- 
chine, through limit switches at bottom of shaft to y. It 
must not be forgotten that by the time the elevator has 
reached the third floor, fingers 11' and 22' are resting on con- 
tact stripy:, and hence are in connection with the wire Z> that 
runs to /. Switches />', A', and C therefore operate as 
before, except that A' allows the current to flow through the 

82 ELEVATORS. g 38 

armature in the reverse direction and reverses the motor. 
Floor magnet 1'' makes contact between ^and^', so that the 
operating current will continue to flow even after the but- 
ton 1' is released. Contacts .9, 9' are also separated, so that 
the push buttons 7, 2, S, ^ are cut out while the elevator is 
in motion. Magnet / is excited and makes contact between 
JO and 10\ thus allowing current to flow to the negative 

line by the path A-ni-l-lO'-lO-r^ , and this current 

holds 10 and 10' in contact, even though the operating cur- 
rent through /" is interrupted by the controller C when the 
elevator reaches the first floor. When the elevator reaches 
the first floor, it is automatically stopped by the controller, 
as already explained, but contacts !? and 9' are still separated 
and contacts 10 and 10' closed, because current still flows 

through the path z-d-d^-d-d-A-A-A-in-l-lO^-lO-r^ . 

The result is that no one can interfere with the elevator 
because pushes /, 2, S, 4 are cut out. This current through ;;/, 
and / remains to flow until the door is opened, thus break- 
ing the circuit at d^ and allowing the armature of 7n and / 
to drop. After the passenger has gotten out and after the 
door has been closed again, thus bridging the break at ^,, 
the elevator may be operated from the other floors, but not 
before; thus avoiding the possibility of accident while the 
passenger is getting out. 

By tracing out the connections and bearing in mind the 
action of the controller C\ the student will see that the car 
is under complete control at all times, and that it is practi- 
cally iinpossibh^ for any person to interfere with the opera- 
lion while anotlu-r person is using it. The unlocking as 
well as the opcniiij^^ of the doors on these elevators is usually 
aul' >inat ic 

oii^ Ai lOM A ri( i:li:( TKic klevatou with no. « 


KM), <.<'in'ral l)t's<*!*i[)li<)n. — The style of floor con- 

liolh !■ show 11 in l-'ii;. -lo and indicated at C, Fig. 45, has 
l)cr!i Mipcr^rdcd l»y a later type shown at (', Fig. 46. Both 
st\]fs air, however, in use, so that it has been thought 



advis^ible to illustrate both nf them. The floor controller in 
Fig, -1*; is considerably different in construction, but it 
accomplishes the same results as the older type; it is 
mounted on top of the motor and driven by a chain it run- 
ning over a sprocket wheel on the end of the drum shaft. 

The controller (' 
not necessary t< 
usual traveling r 
larger view show 
wheel s is revolve 

as a limit switch, so that it is 
lie hoisting machine with the 
■,X a limit switch. Fig. 4T is a 
■ if the controller. The sprocket 
. of the uhain, and by means of 

td. 0»sfecA«^aB^BhcT«f cauB/artkHisetyptvnted. 
■ iwrjwfc M. ns ead a craK«aaiact piece /: the 
tkne nil iil yiiii r b bdcc dtailT txxycatMl bv 
r iHp oae ihw M ^'. Eack fiwitart has a groiivc in 
%■ d pR9B as akafit ^ mr oh gs. thus forcing up 
I the ivo clips 

pMcb it is broaghi in contact- There are two rows of 

I, one iin each side uf the cootroltcr, together with a 

HHKitng namber 'if arms, cams, and cross-coniacl 

The two pairs of large terminals shown at a-, w' 

\ tu the main circuit, contact being made between 

S of the large cross-contact piece ^ and a sim 

llie Other side of the controller. These two it 

I Dpeiated by the arm^ m. m . This controUcJ 

I the same result as the one shown at ^ £ 

■■.* ^ - 

- ■■■' 'i,:!'V VO''''. 

§ 38 ELEVATORS. 85 

Fig. 43, but uses a series of mechanically operated switches 
in place of a series of brushes with a sliding contact. 

lOl, Connections for Otis Automatic Elevator With 
No. 2 Floor Controller. — Fig. 48 is a diagram of connec- 
tions for this type of controller. It will be noted that it is 
very similar to Fig. 45, the limit switch on the machine 
and switch B^ being omitted. The up-and-down magnets 
on switch A' are reversed in position from that in the first 
diagram, but this is immaterial, as the direction of rotation 
of the motor may be kept the same in both cases by revers- 
ing the armature terminals at the motor. The two large 
cross-contact pieces on the controller are shown at ^, g'\ 
and the small contacts are indicated at 11\ SS\ 22", etc., 
there being but three small movable contacts on each side 
in the diagram, because the elevator is controlled from four 
floors only. With the diagram as shown, the car is supposed 
to be at the first floor. All the left-hand contacts of the 
controller are out and all* the right-hand ones are in, con- 
necting the floor magnets fo th'evrline and allowing current 
to flow through the up magnet of switch A' when any one 
of the push buttons i?, 3, or 4 is pressed. As the car moves 
away from the first floor, II' closes, and when it reaches the 
second floor, 22' opens. As it moves away from the second 
floor, 22" closes, and when it reaches the third floor, 33' 
opens; and so on. When the car reaches its upper limit of 
travel, switch g' is opened and when it reaches its lower 
limit, g" is opened, thus cutting off the main current. 
When the elevator descends, the switches open and close in 
the reverse order. The small arrowheads show the path of 
the operating current when button No. 3 is pressed to 
bring the car up to the third floor. The large arrowheads 
show the path of the main current. It will not be necessary 
to trace these through, since outside of the part through 
switch C they are practically the same as explained in con- 
nection with Fig. 45. Ordinarily, the switch ^' would open 
the main circuit and switches^' and ^j^'"" are intended more as 
a safety device in case A' does not operate. 



lO'i. iionvrtkl I>e»friptlon. — The hoisting mechanism 
of this elevator differs in a marked degree from those pre- 
viously described; Fig. 4ft shows 
the general construction. It has no 
winding drum, the cable being 
taken up over a number of mul- 
tiplying sheaves. The hoisting 
rope //, or rather set of four ropes, 
passes over the fi.\ed sheaves S' and 
movable sheaves ,S' and is anchored 
at-1. The motor J/ revolves a long 
screw £, which is directly coupled 
to the motor shaft. On this screw 
is a nut -V, which is not connected 
in any way with any other part of 
the mechanism. A crosshead carry- 
ing sheaves .S' is arranged to slide 
on the base B. and when screw £ is 
e; revolved by the motor, the nut 
^ bears against the crosshead and 
'^ moves the sheaves 5 to the right, 
thus taking up the cable and rais- 
ing the car. The construction of 
the nut .\' and the sheave bearings 
is siu-h that there is very little 
ftiction, and the efficiency of the 
hoisting mechanism is so high 
(about 70 per cent, from car to 
mritiir) that when the car is de- 
scending, the pull against the cross- 
head revolves the screw and motor 
in the reverse direction, thus dri- 
ving I he motor as a generator. The 
slieaves are usually designed (ogive 
a muUiplicatinii of 8 to 1, so that 
the aniinitU of rope that the ma- 
chine takes up is !S times the travel 

§ 38 ELEVATORS. 87 

of the screw. For high rises and high speed, there is 
a further multiplication of 2 to 1 on the counterbalance. 
The ropes lead from the car over the overhead sheaves, 
down around a sheave on the counterbalance, up to and 
anchored at the top of the building. The ropes leading 
to the machine are attached to the bottom of the coun- 
terbalance. There are four of these ropes, as indicated 
in the end view. Fig. 49, two of them passing around 
the eight sheaves on one srde of the machine, and the 
other two passing around the eight sheaves on the other 
side. The travel of the car is, therefore, 16 times that of 
the nut. The screw E is always under tension, no matter 
what the load on the elevator may be and no matter 
whether it be moved up or down. This is necessary with 
this type of elevator because the construction of the nut and 
screw is such that the pressure between them must always 
be in the one direction, and the tension on the rope is the 
only driving power that the elevator has when descending. 
These machines are not, therefore, overbalanced. 

103. Motor. ^The motor used with the Sprague-Pratt 
elevator is of the ordinary direct-current four-pole type 
with compound field winding. It is mounted at the right- 
hand end of the machine, as shown at J/, Fig. 49, and needs 
no special description. 

104. Transmit ting: Devices. — The transmitting de- 
vices of this elevator are of special interest. The use of the 
screw, traveling nut, and sheaves makes the action similar 
in many respects to that of a hydraulic elevator. The 
sheaves are mounted on roller bearings so as to run with 
little friction, and the traveling nut is arranged so that the 
thread of the screw bears against balls. Fig. 50 shows a 
section of the ball nut. Steel balls a are arranged as 
shown, and when the screw turns, these balls revolve and 
work their way along through the nut, passing in at one 
end, traveling through the nut, and returning by way of 
the channel b in one side. The rolling friction of such a 



nut is very much k-ss 
than the sliding friction 
of an ordinary nut. In 
addition to the ball 
nut A, there is pro- 
vided a safety nut Ji, 
which is without balls, 
because under ordinary 
circumstances there is 
no pressure taken up 
between its threads and 
those of the screw. 
The safety nut is pro- 
vided for two purposes, 
namely: to prevent 
shick cable and also to 
hold the crosshead in 
case the threads on the 
ball nut or screw should 
strip. This last contin- 
gency is something that 
never occurs if the ele- 
\ator receives any kind 
of inspection, but as \ 
these elevators are in-' 
tended for passenger" • 
service, it is advisable I 
to take every possible 1 
precaution. When the f 
car is drawn up, there I 
is a thrust between the j 
conical bearing <* and I 
the crosshead that A 
carries the movable j 
sheaves, and since the^ 
friction of this conical I 
bearing is much greater "I 
than the friction of thel 

§ 38 ELEVATORS 89 

screw, the nut does not revolve, but travels along the 
thread, thus pushing the crosshead and raising the car. 
When the car descends, the pull on the rope runs the 
screw backwards, and with it the motor, which now 
runs as a generator. When the pressure on the nut is 
released, the screw continues to revolve on account of the 
momentum of the armature, and the cable would be slack- 
ened if the nut did not revolve with the screw. As soon, 
however, as the pressure on bearing c is released, springs c, 
which are normally compressed, force nuts B and A apart, 
thus bringing the threads of the safety nut into contact with 
those of the screw and producing enough friction to make 
the screw and nut revolve together and thus hold t'he cross- 
head stationary. Again, if the threads of the ball nut 
should wear excessively, or strip, the pressure is taken up 
on the safety nut, which then revolves with the screw and 
indicates the defect. A buffer //, Fig. 49, is provided for 
the nut to strike against when it reaches the limit of its 
travel corresponding to the lowest position of the car. 
When it reaches the upper limit, the end of the nut comes 
up against the shoulder/, Fig. 50, and any further turning 
of the screw simply causes the nut to revolve with it. The 
nut shown in Fig. 50 is the later type using a hollow screw 
of large diameter with |-inch balls. The balls used on 
earlier types of the machine were \ inch in diameter, but 
this size was found to be rather small. The nut shown 
contains 320, f-inch balls. The nut used formerly had 
240, i-inch balls. 

105, Thrust Bearing. — The thrust of the screw is 
taken up by a special form of thrust bearing, which is located 
at D^ Fig. 49, on the back end of the motor frame. The 
thrust is taken upon a large number of small rolls placed 
between two hardened steel plates. One plate is carried by 
the field yoke and the other revolves with the shaft. The 
small rolls, 180 in number, \ inch in diameter by ^^^^-inch 
face, are placed in openings, arranged in spiral form, in a 
bronze plate. A plate containing these rollers is shown in 

Fig. 51 ; this is placed hetween the twn hardened plates pre- 
viously mentifmed, and the whole thrust bearing is arranged 
so as to run in oil. 

Llur is provided with a band 
d. This brake is shown at O, 
steel band lagged with wood, 
e-foiirths of the circumference 
solenoid ^V operates against a 
lagnet is excited the brake is 
agnetized the brake is a: once 


106. Krakc— 1 

brake controlled by 
Fig. 49, and 

The band covers abont ihrt 
of the brake wheel. The 
spring, so that when the i 
released, and when it is den- 
applied by the spring. 

107. Limit Hwltchcs.— Two limit switches /. and /.', 
Fig. 49, are mounted on the base and are operated by pro- 
jections on the traveling crosshead, so that if the sheaves 
reach the limit of their travel in either direction, the motor 
is stopped. Switch L is ordinarily closed, and when the car 
reaches the upper limit of its travel it is opened, thus open- 
ing the main circuit and applying the brake. When the 
car is descending, switch /.' is normally open and when fJ 
is operated at the lower limit it is closed, thus cutting in a 

§ 38 ELEVATORS. 91 

resistance across the motor and gradually cutting it out 
with further motion of the crosshead. A centrifugal gov- 
ernor g is belted to the screw, and if the speed exceeds the 
allowable limit, this governor opens a circuit and effects an 
application of the brake. 

108, Method of Control. — The method of control used 
with the Sprague-Pratt elevator is similar in many respects 
to the magnet-control method previously described. The 
magnet type of controller might be used with this type 
of elevator, but many of the Sprague-Platt machines are 
equipped with a controller in which resistance is cut out by 
means of a sliding arm moved by a small pilot motor. The 
closing of the main circuit and the reversing of the motor is 
accomplished by means of electromagnetic switches very 
similar to those shown in Fig. 40. The pilot motor is under 
the control of the car operator and is operated by means of 
a car-operating switch in a manner similar to that already 
described in connection with magnet control. 

109. Spragrue-Pratt Verticiil Tyi>e Elevator. — Most 
of the Sprague-Pratt machines have been of the horizontal 
type shown in Fig. 49. In cases where two or more elevators 
are required, these horizontal machines are placed one on 
top of the other, thus economizing space, but a number of 
machines have been built so that they may be placed verti- 
cally in the same way as a hydraulic elevator. Fig. 5'^ 
shows the general arrangement of one of tliese vertical 
machines. The motor J/ is at the bottom of the shaft. The 
fixed sheaves ^'i are mounted just below the lower limit of 
the counterbalance, and the movable sheaves .S" travel up and 
down in guides. The rope running to the sheaves is fastened 
to the under side of the counterbalance, and there is a multi- 
plication of 2 to 1 between the counterbalance and the car, 
as indicated. The vertical type has some important advarw- 
tages over the horizontal type. In the horizontal type, the 
long screw always tends to sag more or less, thus producing 
uneven wear. This sai^j^^ini^ cITect also produc-js uneven 
wear on the motor bearings and on the thrust bearing. 




. When the machine is placed in the vertical 
position, these effects are done away with 
entirely, and the additional advantage is 
gained that the weight of the screw, arma- 
ture, and sheaves tends to counterbalance 
some of the thrust and thus reduces the 
efEective pressure on the thrust bearings. 

110. General Description. — This ele- 
vator has not as yet been widely used, 
but as it is very simple in construction 
and easily controlled, it is probable that it 
will prove valuable for many kinds of service. 
It is manufactured by the Otis Elevator Com- 
imiiy. The principle on which the elevator 
o|)eraies is an interesting one and will tje 
understood by referring to Fig. 53; A is the 
c:ir; A' and C two pulleys that revolve in 
opposite directions, as shown. (K is the 
coiiiilerwetfjht and D an endless rope pass- 
ing over the pulleys />', C, and around 
pulk'VS /■ and V on the car and counter- 
weight. I'ullcys />' and C are driven by 
iiHli'|>t'ti<lent sources of power, so that their 
sjii'id with regard to each other may be 
< haniTcd. If the circumferential speed of /i 
i-^ .xui-lly Iht- same as that of C, it is evident 
iIkh iliL- rn]i(: /?\vlII simply pass around over 
ill.; |iulifys:iiid lliv car will remain Stationary. 
It, liiiHi-viT, llie rirniinferential speed of t 
!•- in:idi' i.;r<';ittT thau (hat of />', the rope will 
l>.- ]ias-iiil iiver C' faster than it is taken up 
1>) /; ;i.i.l Liu- car will descend. If the 
I ir^ iiinrianUal speed of />' is greater than 
liuii ni (". llii- rope will be taken up by >■ 
f,i--u-i- tliuo ii is paid out by C, and the car 



will ascend: the greater the difference in 
circumferential speed, the greater is the 
speed of the car. It should be noted that 
the action depends on the difference of cir- 
cuiiifcrcHtial speed, or upon the difference in 
speed at which the rims of sheaves B and C 
travel. Pulleys A' and C may or may ni>t 
revolve at the same speed when the car is 
stationary, depending on whether or not 
they have the same diameter. 

This type of elevator allows the car to be 
stopped, raised, and lowered without stop- 
ping or reversing the driving motors. This, 
of coTirsi', is a great advantage. Usually 
electric motors are used for driving /i and C, 
though steam engines or a combination of 
engines and motors could be used. Another 
advantage of this elevator is that it does 
not require a winding drum with its accom- 
panying gearing. 

in. Fig. 54 shows the general arrange- 
ment of an elevator emiiodying this prin- fio. &s. 
ciple and driven by means of two electric motors. A' and C 
are the tivo pulleys, the circumferential speed of which 
is varied by changing the speed of the motors ni, in'. 
The endless nipe J) is in this case not attached to the 
car, but rnns around a pulley E carried on the bottom 
of the counterweight W and annind the pulley )' car- 
ried on the under end uf the rope-tightening device A'. 
The ropes /, are attached to the car, and after passing 
over sheave J/ are attached to the counterweight. The 
ropes P' also attach to the top of the counterweight, and 
after passing over sheave f/ and throrigh cross-bar •(, are 
fastened to cross-bar 4 of the tighlening device. By draw- 
ing bar Ji down on the tiircaded rods, the ropes can be 
tightened to any desired degre<-. The speed nf the motors 
• is c<intr"lled from the car, and in making a trip they are not 

//. S. y.- 

§ 38 ELEVATORS. 95 

stopped when the elevator stops at the various floors; they 
are merely made to run at the same speed by means of the car 
controller. While the car is ascending, pulley B runs faster 
than C, and in order to make it descend, all that is neces- 
sary is to make C run faster than B, The variations in 
speed are readily accomplished by varying the field strength 
of the motors. The controller is arranged so that when the 
handle occupies the central position, the speed of both 
motors is alike and the car is stationary, and when moved to 
either side of the center, the speed of either one or other of the 
motors is changed. A small auxiliary-operating handle is 
also provided in connection with the main handle, so that by 
pulling up on it the operator can stop both motors when the 
elevator is not in use. 


(PART 3.) 



1. Hydraulic elevators are still considered by the 
majority of engineers as being the most suitable for large 
passenger-service plants with their high lifts and great 
speeds, although the electric elevator has since its advent 
become a powerful competitor. The hydraulic elevator is 
intrinsically safe, reliable, smooth-acting, and under perfect 
control. It requires comparatively less care in operation 
than the electric elevator, the mechanism being very simple. 
The cost of maintenance is small, the wearing parts being 
few and easily and cheaply replaced. 

On the other hand, the hydraulic elevator is cumbersome, 
requiring much space, especially — and this is the case in 
most large plants — where the water pressure available is not 
high enough for direct use in the elevator cylinders, so that 
the installation of steam pumps, reservoirs, or tanks, and 
the necessary piping becomes necessary, not mentioning a 
boiler plant, which we may assume, for the sake of the com- 
parison, as being already in existence for other than the ele- 
vator service. Thus, the first cost is great compared with 
that of an electric elevator plant, which, in case the right 
current is already available, either from a central station or 
from an isolated lighting plant in the building, consists of 

§ 39 

For notice of copyrij^ht, see paj^fe iininediately followinj;: the title page. 

2 ELEVATORS. § 39 

the elevator machine only, which may even be placed on top 
of the hoistway, and in case the current must be generated 
expressly for the elevator, of an additional steam-engine- or 
gas-engine-driven dynamo, but no cumbersome tanks or 
piping. The installation is thus simple and cheap, the 
space needed but small. There are advantages, then, in 
both systems, and which one to select depends on many cir- 
cumstances which must be weighed against one another by 
the architect and owner, but not by the operating engineer, 
who should have no prejudice against the one or the other, 
but should be equally familiar with both. 



2. The simplest kind of hydraulic elevator is the dlrect- 
tu*tin^ or plunKtM- elevator. It is also the oldest kind of 
hydraulic elevator and has been used for a long time, both 
for freight and passenger service, for short lifts. It has 
been until recently c(msidered unsuitable for high lifts and 
high speeds, and is therefore found installed in great 
numbers as yet only for sidewalk lifts, slow freight ele- 
vators, and simihir service. Lately, however, the possi- 
bility of using this type of elevators for greater lifts and 
si)eeds has been recognized, and it is safe to predict that they 
will be more frequently installed than before and for even 
the severest service. 


3. Fig. 1 shows a plunger elevator made by Morse, 
Williams l^ Co., of Philadelphia, Pennsylvania, for short 


4. Motor. — The mot(^r in this machine consists of a 
vertical cylinder J sunk into the grt)und below the bottom 
of the hoistway and a plunger /\ The cylinder is closed at 

the bottom aod has an enlarged head above ground contain- 
ing the stuRingbox li and an opening for the pipe through 
which the water under pressure enters the cylinder and is 
discharged from it. The cylinder must, of course, lie sunk 
plumb. If the subsoil is soft earth, it is first necessary to sink 
a steel pipe C, called the casing, through which the earth is 
removed. When the subsoil is nK'k no casing is required, 
the hole for the cylinder being drilled. 

Fnr high lifts the cylinder is made up of sections. The 
Plunger Elevator Company, of Worcester. Massachusetts, 
use steel tubing, which they square up and thread in the 
lathe, connecting the sections by means of couplings. This 
insures a perfectly straight cylinder. Before burying in the 
ground the cylinder is tested and given a coat of preservative 

The plunger when required to be long is also made up of 
sections of steel tubing. Fig. a shows the special joint 
used by the company named above. The 
plunger is turned to uniform sire and pol- 

5. Tninsmlttln^r Devices. — As the rar 

rests directly on top of the plunger, there 
are no transmitting devices, such as drums, 
ropes, and sheaves. The car is fastened to 
the plunger, which is provided with a 
head //for the purpose. The head shown 
in Fig. 1 is simply a cast-iron plateclamped 
to the plunger. This arrangement, while 
sufti(,ient for unbalanced small elevators, 
would be dangerous for large counterbal- 
anced ones, inasmuch as should the connec- 
tion between the head and the plunger give 
terweights would jerk the car upwards against 
Great care is, therefore, taken in bal- 
e the aforesaid connection 
iner in which this is done 

way, the 

tile overhead work. 

anced elevators of this kind to 

very rigid and reliable. 

by the Plunger Ele^ 

r Company is shown in Fig. 3. 

§ 39 ELEVATORS. 5 

The plunger has a flange formed on its upper end that fits 
into a corresponding recess of the head //. The latter, in 
turn, is securely Imlted to the framework of the car plat- 
form. Besides this flange connection a second security 

against the parting of the car and plunger is provided by a 
tie-rod R which runs all the way through the plunger, 
through the bottom of the same, and through the framework 
of the car platform. Instead of the rod R a loop of galva- 
nized iron rope is often used for the same purpose, 

6. Counterl)alaiM-ing. — Low-lift plunger elevators are 

generally not counterbalanced at all. High-lift elevators 
are counterbalanceil, but n<)t overbalanced, since the power 
acts only on the up stroke of the plunger. Enough of 
the weight of the car and plunger is left unbalanced to 
secure the descent of the car at the proper speed when 
empty. The upward pressure of the water on the plunger 
gradually diminishes as the plunger goes up by an amount 
corresponding to the increasing height of the water that 
displaces the phingcr. To equalize this change of pressure, 
the counterweights arc suspended from cables of such size 
that the weight per each foot of their length passing over 




the overhead sheaves will be equal to the weight of 1 foot in 
height of water displacing the plunger. 

7. Controlling: Devices. — The controlling devices con- 
sist simply of a balanced three-way water valve operated by 
a simple shipper rope, or a shipper rope in connection with 
some more elaborate operating device. The simple shipper 
rope is generally used with the smaller machines, while an 
operating device of more elaborate form is used for the 
larger machines. 

The valve in a hydraulic elevator constitutes the only 
controlling device, being power control and brake at the 
same time. As a power control it shuts off the power at 
the will of the operator; as a brake it is so designed as to 
shut off the water gradually by throttling. This object is 
most easily attained by a piston valve, which type of valve 
is used exclusivelv. Thus, while there is no brake in the 
common meaning of the word in hydraulic elevators, it is, 
nevertheless, there as in any other elevator, but in a differ- 
ent form. 

This identity of power control and brake is one of the 
intrinsicallv valuable features of the hvdraulic elevator, 

since by opening the water pas- 
sages more or less, the speed of 
the car can be regulated to a 
nicety and in harmony with the 
load it carries, which feature is 
not easily attained, if attained at 
all, in anv other kind of eleva- 
tor. Generally the valve is pro- 
portioned by the installators so 
that when fully open it will give 
the empty car the maximiun 
speed permissible; but by the use 
of stops tlie valve throw can be 
adjusted to any car speed. Such 
sto|)s are j^cnerally in the shape 
I'lf; I of knobs or buttons clamped to 


the shipper rope and striking against some fixed projection, 
as shown in Fig. 4. These stops are called back-stop but- 

8. The valve used on the Morse, Williams & Co.'s 
elevator is shown in section in Fig. 1. A peculiar feature 
of this valve is the shape of the piston /, which is seen to be 
wedge-shaped, in consequence of which the water passes to 
and from the machine gradually and without shock. The 
operation of the valve will be readily understood from the 
drawing; on shifting it one way by means of the shipper 
rope passing over the sheave Sy water flows from the supply 
into the machine and exerts a pressure on the plunger, lifting 
it and the car. By shifting the valve in the opposite direc- 
tion, communication is established between the machine and 
the discharge, and the elevator descends. In the interme- 
diate position, the valve shuts off all communication of the 
machine with the supply and discharge and the elevator is 
at rest, the plunger being supported on a column of water 
confined in the cylinder. 

9. In larger machines the controlling valve is preferably 
moved by a motor piston, which is operated by a pilot 
valve. The pilot valve is in turn controlled by the shipper 
rope from the car. The arrangements of pilot valves and 
main valves differ in different installations, but are easily 
understood in every case by inspection. We shall encounter 
the pilot valve again in connection with piston elevators, 
when descriptions and drawings of several types will be 
given and their purpose explained. 

■ lO. Safety Devices. — The plunger elevator is the safest 
elevator built. The ordinarv knobs or buttons used on the 
shipper rope as limit stops are the only motor safeties pro- 
vided, and even should the limit stop fail to operate the 
valve at the top of the run, the counterweight would reach 
the ground and the car stop ; should the limit stop fail to 
operate at the bottom of the run, the car would simply come 
to rest on the cylinder. In order to avoid damaging the 
cylinder head in case this should happen, buffer springs are 

§ 39 ELEVATORS. 9 

often placed on top of the cylinder head, especially when 
the speed of the elevator is considerable. Car safeties, 
which are essential on all other elevators, are not needed in 
plunger elevators, for the car cannot fall, since the plunger 
always rests on a column of water that is driven out through 
comparatively small openings; it may, however, in case the 
valve should fail to operate, attain a speed that would be 
undesirably great, though not dangerous. To provide 
against this, the simple expedient of putting in the discharge 
pipe a throttle valve controlled by the pressure correspond- 
ing to the velocity of the exhaust is resorted to when 
necessary. The car cannot be violently pulled against the 
overhead work by the counterweight as long as the connec- 
tion between the car and the plunger is secure, which 
security is easy of attainment. 



11. While the plunger elevator treated in the previous 
articles is simplicity itself, it has some disadvantages. The 
hydraulic cylinder and plunger must have a length equal to 
the lift, and for each trip of the car a volume of water is 
used equal to the area of the plunger multiplied by the lift. 
In the piston elevator, by introducing multiplying sheaves 
the hydraulic cylinder can be made considerably shorter, 
and thus the volume of water used for each lift reduced 
accordingly. There are two types of piston elevators in 
general use. In one the cylinder is vcrtictxl and in the other 


12. The vertical type is considered better than the hor- 
izontal type, and is always installed when circumstances will 
permit, chiefly for the reason that generally headroom is 
more available than floor space. Fig. 5 is a section through 



the cylinder,. pision. 2 
kind, as built by Moi 

valve of a simple machine of this 
Williams & Co.. of Philadelphia, 


13. Moior. — Following up the various parts, we have as 
motor a cylinder .-! and piston P, the former consisting 


of a number of cast-iron flanged sections bored and faced 
true and bolted together at their flanges; a bottom head A J 
and a top head A', which latter contains the stuffingboxes for I 
the piston rods /and/'. The cylinder has two openings*! 
and ii'. at the top and bottom, respectively. 

14. TranBinlttluK Devlt^es. — The transmitting devic 
consist of wire ropes nmning over sheaves, one or more of 
which are carried in a yoke j attached to the piston rods, 
white the others are supported in bearings on overhead 
beams. The main figure shows but one travel Ingr sheave 7"; J 
the car in this case moves twice as fast as the piston, and! 
the elevator is said to be geared in the ratio 2 : 1. Fig. &M 
(a), (fi), and (c) shows the arrangement of sheaves for thefl 
ratios :) : 1. 4 : 1. and 6 : 1, respectively. 

15. Counterbalancing. — As we shall see presently J 
matters are arranged in most vertical elevators so that thi 
cylinder is always full of water. This gives rise to an"| 
advantage in counterbalancing. The piston is always car- 
ried on a solid column of water and thus forms a counter- 
weight that will come to rest at the moment when the power 
is cut (iff, that is, the flow of water stopped; contrary to a 
free counterweight, it will thus not produce a tendency I 
teeter the car up and down by its momentum when I 
power is suddenly cut off. The counterweights i 
elevators are, therefore, preferably placed wholly or at lei 
partly on the piston or piston rods, as shown in Fig. 
(i). and (c). As the power acts only on one side of the ( 
ton, the counterweights must be less than the car weight h 
an amount sufficient to make the car descend at the prop* 
speed when empty. 

§39 ELEVATORS. 11 

16. Controlling: I>eviee. — The controlling device con- 
sists of a balanced three-way valve operated by a shipper 
rope in the usual manner, the rope being provided with 
back-stop buttons. The action of the motor under its con- 
trol is as follows: The space of the cylinder above the pis- 
ton is always filled with water under pressure, the supply 
pipe being connected with this space directly through the 
circulating: pipe C, The other end of the circulating pipe 
is connected with the space of the valve chamber between 
the two valve pistons. If the valve pistons be moved down- 
wards, so as to bring the upper valve chamber and thus the 
space of the cylinder above the piston into communication 
with the space below the piston, there will be the same 
water pressure on both sides of the piston. The car, being 
heavier than the piston with the counterweights, will cause 
the latter to ascend while it is itself descending, and will 
force the water from above the piston through the circula- 
ting pipe into the space under the piston. For the ascent of 
the car the valve pistons are raised so as to put the space of 
the cylinder below the piston into communication with the 
discharge pipe; there is then pressure only on top of the 
piston, and the same descends, raising up the car. In 
the position shown in Fig. 5, the valve closes the space below 
the piston against both the supply and the discharge, so 
that the piston is held between the water pressure from 
above and a confined water column from below. 

The object of making the water circulate from the top to 
the bottom of the piston is primarily to make the effective 
pressure on the piston the same at all points of the stroke, 
which otherwise would not be the case. Imagine that the 
cylinder was open at the top and bottom and the piston at 
the top of its travel, and that water be poured on to the pis- 
ton from above; then the latter would descend under the 
influence of the weight of the column of water above the 
piston, which would be nothing at first, but would gradually 
increase towards a weight equivalent to the total contents of 
the cylinder. Imagine, now, that the space below the piston 
is filled with water, the piston again being at the top; then 

!:» ELEVATORS. §39 

ihe C'll-imn :: Titer -mirrrieith it will exert a suction on 
the t:>t " c rrr>t- r.iir.j: t> the height of that column, as 
!■ -ng i> the : lur::" :> r. t hii^hcr than ;M feet, which suction 
will ^a..iuil'.y ..:e\;reo<c t.- n- thin^^ as the piston descends. 
Thus by hi vine -he spa:e b^'.ow the pist«»n tilled with water 
the same net r'.rce :s exerted ••a the piston at all points; 
f "T, while the i>re>sure ■ f the water above it increases, the 
sucti'-r. vf the water "r-^l.w it decreases at the same rate. 
In c«>ncise technical terms, then, the object of the circula- 
tion or the water fr- m the t"p t*- the b«:»ttom of the piston 
is t'j balance the head •: the water ab:)ve the piston. 

17. Safely lK*vlces. — The safetv devices consist of 
the usual *:/»- j\/ v;:t\> ::>ed for susj>ended cars and motor 
Sti r\'tu's. Limit >t- -r-s takr the shape of knobs or buttons l\ l\ 
Fig. .1. "n an endless r v-e ^\ which are operated by a 
pr«»jecting arm ;/ **n thv piston nxi. The top and bottom 
heads would •»! v«>iirse >t •{> the travel oi the piston either 
way. but it w. »u!d n-t l*e sate to intrust them with that 
duty, as breakage may result by the piston striking them. 
The latter sh'»uldnvt. thcref«Te. ordinarily travel so far as to 
strike the heads. There being a {>*ssibility, however, that 
this mi'.:h: "ccur :hr- i:^h .t t.ii.iire ••! the valve to ojK'rate, 
the pistvn is pr'«v:<.ie'.i \v::h an apron / i^n each side; each 
apron has a number •: •-.••les :. : thn»ugh it and partially 
cl'-ses the P'«r:s .' '<v . arv.i thus reduces the sp)eed of the 
pist'»n betfre i: re.ich. < ::.e heaiis. The holes /, / allow the 
water t'» enter •■:■■ t:;e return str-.-ke. 

18. It • cit: e.i-:!v be understo-Hl that everv elevator 
sh«»ni.i ;.f >t.i-te-: ar...i st'»pped gradually to avoid shocks, 
and that t;.: re .r.uays exists the danger ot overthrowing 
the coritr' -liin^ 'iev.ce bey-^nd the neutral ])<)int. 

Referrir.g :•. Fi-. .">, it will be un^^ierstood that when the 
piston i> g«'ir.g r.«.\vn tiic car is ascending, and if the valve is 
suddenly cl' »>♦••!, the ti<'\v ot the water ln>m the space below 
the pist<»n thr<'Ugh the <lischarge pipe is suddenly stopped. 
The momentum «»t the pi>t<>n and car will tend, however, to 

§ 39 ELEVATORS. 13 

continue the motion, resulting in a thud of the piston 
against the column of water thus confined. To avoid this 
Mrater ram, as it is called, it is good practice to interpose in 
the discharge pipe between the cylinder and valve a relief 
Talve r, as shown in Fig. 6, which is a drawing of an Otis 
vertical elevator of much the same design — with the 
exception of some details, to which we shall refer below — as 
that shown in Fig. 5. The danger of producing a shock by 
the careless handling of the operating device on the down 
trip of the car is not so great, inasmuch as the column of 
water above the piston is not confined in the cylinder on 
closing the valve, being always in communication with the 
supply pipe and through it with the pressure tank and its air 
cushion. A relief valve for the down trip is, therefore, 
deemed superfluous. 

19. Pilot Valves. — For high-speed hydraulic elevators 
((>00 feet per minute and more), the insertion of the relief 
valve is not sufficient to guard against shocks, it being 
extremely difficult to start and stop gradually by operating 
the main valves directly ; nor is it possible to regulate the 
speed readily by opening the valve more or less, so that one 
of the most valuable features of the hydraulic elevator is 
curtailed. This has led to the introduction of the auxiliary, 
or pilot, valve, already referred to in Art. 9, Such a valve 
as built by the Otis Elevator Company is shown in Fig. 7, 
of which the following is a brief description : 

Contrary to the direct-operated valves shown in Figs. 5 
and 6, the main valve V, Fig. 7, composed of the pistons v 
and 7'\ is not balanced, but the upper piston zf has a larger 
area than the lower double one r ; the valve is, therefore, 
also called a dlflferentlal valve, there being always a pres- 
sure against the under side of the upper piston t' depending 
on the difference between the areas of the pistons Zf and 7/. 
On a bracket B fixed to the main valve casing is supported 
the auxiliary, or pilot, valve IV, which is simply a piston 
valve of small dimensions; the casing of this valve has an 
inlet tv connected with the circulating, or supply, pipe and 


16 ELEVATORS. §39 

an outlet Ti-' lonnected by a pipe to the space above the 
upper piston of the main valve, as shown. In the position 
of the two valves shown in the illustration, the communica- 
tion between them is shut off, the pilot-valve piston cover- 
injr the outlet port. The upper space of the main valve is 
fille<l with water whollv confined, so that the tendcncv for 
upward motion of the piston i* is checked in a position where 
the lower piston cuts off the circulation of the water, when, 
as we know, the elevator is at rest. By lowering the pilot 
valve, communication is established betw^een the supply, or 
circulating, pii)e and the space of the main valve above the 
piston i', which i)resents its whole area to the incoming 
water: as the upward pressure below it is less, owing to the 
difference between its area and the area of the lower pis- 
ton r'', it will descend with the effect of allowing a circula- 
tion of water from the top to the bottom of the cylinder, so 
that the car descends. If, now, the pilot valve be brought 
hark into the position shown in Fig. 7 (the main valve being 
in its lowest position for the down trip of the car), it would 
check any farther downward motion of the main valve and 
the same would thus remain set for the down trip. Again, 
if the ])ilot valve were raised beyond the position shown in 
Fi}^. T (the main valve still being in its lowest position), the 
space al)()\(' the piston :• would be connected with the 
exhaust and the main valve would ascend and keep on 
ascending to the neutrid position (elevator at rest) and 
beyond it (elevator dcseending), unless the pilot valve be 
l)rou<;lu hark to the neutral ])oint. 

Thus, it" no provision he made furtiier than described, it 
would he necessary, in orde'- to stop the car during a down- 
ward trip, t'» thi*o\v the pi lot. -valve operating device com- 
pl<-tely over. l<> wait until the elevator (\'ime to a stop, and 
thru t<. throw the (ievi<e into the central (neutral) position. 
TIk- >anie complicated operation would be required for the 
upward trip. 

*^<>. To avoid the (omplicated oj)eration mentioned in 
Art. 10, the two vaUcs are so connected by a system of 

§39 ELEVATORS. 17 

linkwork that the pilot valve closes automatically without 
affecting the operating device in the car (shipper rope, lever, 
or hand wheel) when the main valve reaches its extreme 
upper or lower positions. This is brought about in the 
following manner: The shipper sheave S is mounted on the 
bracket B, its shaft s carrying a crank T, the crankpin c of 
which is connected to a double-armed lever M by a link L 
and a pin m. To the right of the pin /// is another pin ;//' 
that serves as a pivot for a link yV, which is connected at the 
other end to the stem of the auxiliary valve. A third 
pin m'\ to the left of the pin /;/, connects the lever Af with 
the main- valve stem. Stops /, /, /' on the shipper sheave 
and its stationary bearing, respectively, limit the motion of 
the crank C, 

The operation is as follows: Starting, as before, from the 
position of the valves shown in Fig. 7, the piston 7' is held 
stationary between the water pressure from below and the 
confined water above, so that the pin ///" forms the pivot of 
the lever J/ when we move the shipper sheave to the right. 
The crank C then pulls down the lever and with it the 
pin ///', link A^, and the pilot-valve stem, thus lowering the 
pilot valve to the position in which it admits water into 
the main valve, which then moves downwards. As soon, 
however, as it commences to move, it raises up the pilot 
valve, the crankpin r, as well as the link L and the pin ;// 
being now stationary, which latter then serves as the pivot 
for the lever J/. The leverage is so proportioned that by 
the time the main valve has reached its lowest position the 
pilot valve will be closed, that is, it will have returned to 
the position shown in Fig. 7, checking further motion of the 
main valve, the crank C, however, remaining in its lowest 
position. If it is now desired to stop the car during its 
down trip, the sheave, and with it the crank, is brought 
back to the neutral position. The pin /;/" being, now, once 
more the pivot for the lever J/, the pilot valve is raised 
above its neutral position, the main valve rises, and by the 
time it has risen far enough to shut off circulation of the 
water it has dragged the jiilot valve back to its neutral 



(x»<ition. Ail pans are now again placed as shown in Fig. 7 
iiUf] the* rycle may Ije repeated. 

tfl. Though it takes many words to describe it. the 
op#- ration of this valve is very simple and reliable. The 
oj»#:rator may with impunity throw the operating device 
quif kly from its neutral position to the right or the left, 
that is. for ** up " **r •"down." without affecting the gradual, 
m^rasured moti«»n of the main valve, which is the purpose 
of the pilot valve. Moreover, it will be understood that 
the pil'it valve all<»ws a perfect regulation of the speed 
of the car. For by throwing the operating wheel or lever 
on the car over only part of its full swing, the pilot valve 
will make only part of its travel and, consequently, will be 
brought back to its neutral position by the action of the 
main valve bef«>re the latter has completed its full stroke, 
thus 1 (raving the main valve but partly open, whereby the 
flow of the water is throttled. 

22. Independent Top and Bottom Stop- Valve. — In 

ronnecti'Hi with a pilot valve, the ordinary kind of limit 
st'»i) shown in Fij^. ") operating the valve directly cannot 
be used, for the ])isi()n or ear will still be moving, while the 
quick move of tlie pilot valve has long been completed. It 
l)e(<»nies necessary, then, to introduce an indef)endent valve 
for stnppin;^ the car at its limits of travel. Such a valve is 
shown in I'ij^. s at O, and its construction and operation are 
as follows: Into tlie ])assage leading from the space below 
the (levator pist<»n to the exhaust, a cylindrical shell g 
havini^ thifc passaj^es is inserted, of which the upper 
j»assaj;(' leads to the relief valve (see Art. 18). Either of 
tin- iw<i })assaj^('s / and /' may be closed by the rotary valve, 
shown to an enlarj^ed scale in V'i\!;. i», which consists of a 
spindle s })assini;' thronj^h stuffinghoxes of the valve casing 
and carry inii ^i valve body :* composed of a sleeve and 
11an.L;('S lillin;^ tlic inside of the shell (/. The flanges of the 
valve i)ody ar<' n<»tched out to recx'ive the valve proper u\ 
whi< h fits with considerable play in the ncUches, as shown 




X. t 

casing a gear-wheel^, Fig. 8, actuated by a weight If that 
tends lo keep the valve in the neutral positinn shuwn 
in Fig. 8. The gear ^meshes with a smaller gear attached 

10 the shaft of a rope sheave S, which is actuated by an 
endless rope passing over an idler above and carrying the 
usual stop buttons. Now, when the piston nears its lowest 
position, the arm a on Ihe piston rod strikes the lower stop 
button; the sheave i' swings right-handed and the valve tc 
turns left-handed, covering up the right-hand port or pas- 
sage /, thus shutting off gradually the communicatinn uf 
the cylinder with the exhaust and stopping any farther 
downward motion of ihe-plsttin, even if the operator has 
neglected to move the pilot valve. '' 

In order that the elevator may start again upon reversing 
the pilot valve, the valve w of the rotary stop-valve has a 
certain play, as already stated. Thus, imagine the piston 
in its lowest ptisition and the valve w covering up the port f ; 
it will then be pressed against its seat {the shell ^) as long 
as the main valve uncovers the exhaust or is in the middle 
position, by reason of the pressure above the piston. But 
as soon as the main valve is reversed, so as to open commu- 
nication between the spaces above and below the piston 
through the circulating pipe, there will be an excess of pres- 
sure against the outside of the valve n' of the rotary valve, 
due to the unbalanced weight of the car. The valve ;c' will 
then be lifted off its seat and will allow water to pass below 
the piston, which then commences to rise. Presently, the 
arm it will leave the lower stop button ami the rotary valve 



. . ^ - — .■t 

u:r:k' :ii->it:'»n bv virtue of the 
!ir ioii'-n takes place at the 


ir.r r»:"i:«>n. 

2i{. 1 hn»iiU-. — A ::~rrrr.ce will l»e noticed in the con- :: r. : :r.r r: .-.■'. vilve ii^twern that shown in Fig. 7 
2:.i ::...: >h »-r. [- F:^. <. :hcre Ixring interp*>sed in the lat- 
: r « ..-r i -:-:.-/. -'.r-rvr '-riwcrrn the upper single piston and 
::-.e I *.vrr : •.:• Ir •::•--. This sleeve, which is called the 
thn»TtU* :*r. : i-^ cr>:»:r.a:r.: by 7". Fig. s. is fastened to the 
V... .--r r •:. r s:v:r., .-.r.v! in its neutral positi^m shuts off 
t : . v > v: ]]'•'/ :r ::: : : . •- - : a o e ! -e : ween t he va 1 ve pi s t on s. O t her- 
w.-r. ::.- -. :•■.•. .:• vs ar. ! :-assag:es are the same, the supply 
:•::.: in c "-:..:.: o :v.:r.ur*:cai:vn^Hrxcept when shut off by 

& - ■ * 

■ - •■-^ • « T -"j • ■ w^ 

itir.'^ pipe by two branch pas- 
:i*"i:!:ir chamber around the throttle 

: • ::;tr ■. :r-. u*.. -.::.- .: :::'v. In order to show this clearlv, a 
:. r:.: :.:..! s- :: :: :::r i^h the middle of the throttle and 
;:- ■ "<::.^' i- ^:vr:\ :•• :•.". f::^:irvred scale in Fig. 10 {a). 



?!■; :.V 

Tho })i.iri.'.s»j .■!" ihr ilip'tlK' is a threefold one. (1) It 
s<Tvr>. it can-fuliy aojustid. to deaden the noise occasioned 
by th<: <ir< iiiaiinu: watrr. CI) It starves as a brake while 
dcsctMidin^, in rase ui an extra luatl «>n the car, preventing 

§ 39 ELEVATORS. 21 

it from attaining undue speed. This is accomplished by the 
top of the throttle sleeve being partly closed, as shown by 
the plan view given in Fig 10 (^), thus allowing only a 
small amount of water to pass through, that is, throttling 
it. (3) If any pipe or connection between the supply and 
valve should break, the water cannot back up from the cir- 
culating pipe out through the supply port faster than it can 
leak around the outside of the throttle. 

24. The throttle is but loosely fitted to its seat, or 
lining, so that there is always some leakage around it, other- 
wise the elevator could not be started from its position of 
rest, since there would be no outlet for the water between 
the large and small piston of the differential valve while 
descending, and to the inlet while ascending. This leakage 
is sometimes solely depended on to give the differential 
valve the initial start, but oftener a by-pass pipe x. Fig. 8, 
leads from the supply chamber of the pilot valve to the 
space under the upper piston of the differential or main 
valve. This pipe is provided with a globe valve, by 
means of which the rapidity of the initial start can be reg- 

25. I>ouble-PoAver Vertical Ilyclraullc Elevator. — In 

modern office buildings safes and other heavy furniture are 
frequently moved about, and one of the elevators in such a 
building is, therefore, generally designed for a much heavier 
load than the others. The necessary power is obtained from 
an extra-high-pressure tank. In order, however, that this ele- 
vator may be used for ordinary loads as well, with nn greater 
expense than the others, a special valve is used that permits 
it to be used at will either with the ordinary low pressure or 
with the high pressure. Such a valve, built by the Otis 
Elevator Company, is shown in Fig. 11. The upper valve v 
is, in this case, a i)iston valve straddling in its neutral and 
lowest position the high-pressure port. The throttle 7" has 
ports /, /. When the valve stem is moved down, the water 
circulates as in the ordinarv hydraulic machine and the car 
descends. When the valve stem is moved up, the discharge 

7 X:^ §39 

■-.i •- '7. i" : i> '.Z't -oT-pres- 

: - : :--: .-. >.r. irr thr«»ugh 

-J -. zr: -'. i-i-r* the Car l<» 

:-.T - ^'ii-zr-rss-re inlet r. and 

:. j--:rT>--jrr Titer ini-.i the 
•t t« r-> .*. -" ir.i the circula- 

: '.z : J . . "• r: r. T f t « :' the high 
: : -'-: vilve^ the Imw- 

.17.-: tt: -ri-.h the circulating 
' :-.T -s-^ T uM rl'i'W frum 

— -tr-r^s-re t^r.k. were it not 
-."T .. T.-_rrs--rr sut't'iy pipe. 

'^♦5.« !n-TilaTlnff •^y^em-i, — Ir. the vertioai-piston 
-: :■--:-•--:'- . . :::v listir^-ii^hin;^ feature was 
■ - - -■ : : . - - -■. 7- :r -T. ^■■- ve the i»i>t«"»n t'»the 

- - .-. r.^- : 7 :i- er.t : the ar. As we have 

- ■- -•.--. H5. *. ; -.:. :; ^1 ': ;r t : thi> arrangement 
.. - : : ■■'..' J. : ■./.-.- r.-rJi 1 : thv ^^ter ab-'ve the piston. 

- :. -- :. Ji :-.i:.:-^--- .n . ur.terbalancing were 

'.'. > - ■ ': ■ ■ 7: :: -r :-.i: ^ rati-i ■: •; : 1 is the 

.* : .' ■ ■ • :.......--. I:: .-.-rtJiir* designs, however, 

— - . .^rr. 1 ::-..; '.. .-.: ve this value tor the 
; •; -■ • ::..i-: .: : :■ ;!.:. !-r v-rry >ma'l. Now. since 
*-• ■■ i : : ' .:'.■- ■ ::; .- "v-- .-.I'.d !f>> the shorter the 
'j.'.l-- - :.- ■:. .-. :r - - -.:•.. v^^iry t ■ "iKiiance it when 

-■••' " -• - _ . - .; '.':'.. !■ r :::<tance. In such 

'ii-T- •:.'; ■. .: .-.: ^ : ■ > .-i.r:— ; with: the water then 
(•lit* r- :;:. i !• .. - ■ . :•- -. ; . : :'-■■ •.>:■ :\ ..nlv and one end 
of tiic '.!;•.':»:?■ > ;■ :* • - :. :■■ :h.- .itin-spherc. Fig. 1:J 
sh'iws a:. • ,• vat r . : :;.> ;^::;.i :::,..:,.• l.y The Whittier 
Ma* liirii: (!'.MiT*ar.; . : I;.-*. ■:-. Tji-rr.- a-t- i^uite a number of 
lhr:si: nia« liiufi :•. j/'-rat:- -i;. T'::'.- raii«- "f the particular 
mac.:liin<: iliii^irai- 'i i- In : J. \i\,vt: \n:iu-^ a set of five fixed 
and fi\': lra\':!ir!- -hra\>:s '.n t-arh >'u\r -.f the cvlindor: 


fr<>rn each of tlie two sets a rope passes to an overhead 
sheave and thence to the car. The fixed sheaves are 
arranged below the trav- 
eling sheaves, the latter 
being attached to a 
crosshead carried on the 
piston rods and guided 
on rails R, R. The pis- 
ton moves u/> for the 
ascent of the car and 
down for the descent, 
so that the piston rods 
are in compression. 
Moreover, the piston 
moving in the same , 
direction as the car can- 
not, as in the case of the 
previously described ver- 
tical machines, be util- 
ized as a counterweight, 
but must itself be coun- 
terbalanced, which is 
done in the manner 
shown in the illustration, 
\V, IC being the weights. 
The controlling valve is 
much of the same con- 
struction as that shown 
in Fig. 6. 

87. While in- high- 
ratio vertical elevators 
of the kind shown in 

Fig. 12 the circulation of water is dispensed with, owing 
to the small head of the water, it bL-conies entirely dis- 
pensable when the cylinder is placed horizontally. All hori- 
zontal hydraulic piston elevators are, therefore, based on 
the non-circulating system. 

§ 31> ELEVATORS. 25 


J88, Advantages. — Although the floor space occupied by 
a vertical elevator cylinder is comparatively small, this floor 
space is required on each floor of the building, and where 
there are a number of elevators, the aggregate necessary 
space amounts to more than can in many instances be con- 
veniently spared. Moreover, it becomes necessary, in case 
of a battery of elevators, to provide a separate well for the 
cylinders. Again, the long, upright cylinders so placed in 
a comparatively narrow well are inaccessible for the greater 
portion of their length. Ft)r these reasons preference is 
given to the horizontal type of elevator when there is suffi- 
cient floor space more available in the basement of the build- 
ing than on the floors above. Rut under the most favorable 
conditions, floor space, even in the basement, is always limi- 
ted, and it is desirable, therefore, to make the cylinders short, 
which necessitates a high ratio of the transmitting devices. 
This is generally chosen as 10 : 1. The sheaves in these 
machines are arranged either so as to put the piston rod in 
compression or so as to put them in tension. 

29. Coiiipressloii Type. — A simple machine of the com- 
pression type, built by Morse, Williams & Co., is shown in 
Fig. 13. The fixed sheaves are placed at the rear end of the 
cylinder and the hoisting rope is carried above and below 
the cylinder from the fixed sh(!aves a to the traveling 
sheaves b back and forth and is finally led otT from the former 
to the car. The drawing calls for but little explanation. 
The controlling device consists of the three-way valve illus- 
trated in Fig. 5; the motor safeties are limit-stop buttons 
carried on an endless chain or rope and actuated at the 
extreme positions of the piston by an arm or projection ron 
the crosshead d. The endless chain runs over a sprocket 
wheel fastened to the shipper-sheave shaft. 

30. Tension Type. — The general arrangement of the 
tension type of horizontal hydraulic machines is shown in 
Fig. 14:. Both the fixed and the traveling sheaves are 

§ 39 ELEVATORvS. 27 

located at the front end of the cylinder. It will be noticed 
that the traveling sheaves a, a are mounted in the crosshcad 
at an angle to the horizontal plane. This is necessary in 
order that the ropes shall not **ride" off the grooves when 
the two sets of sheaves come close together at the end of the 
stroke. This precaution is deemed unnecessary in the com- 
pression type, the sheaves being always apart a distance 
greater than the length of the cylinders. 

There are several advantages in the tension type of 
machines: (1) The piston rods can be considerably smaller. 
("l) The distance between the fixed and traveling sheaves is 
smaller, being only about one-half as long as that in the com- 
pression type; this is an item of importance when the fact is 
taken into consideration that teetering of the car is often 
due to the whipping of the ropes in horizontal machines, 
which action increases as the distance between the sheaves 
becomes greater. This action, by the way, is absent in 
vertical elevators. The whipping of the ropes is reduced 
as much as possible by supporting rollers shown in 
Figs. 13 and 14. In the tension type these rollers are sup- 
ported on a shaft that again rests on guide shoes traveling 
on rails. 

31» The compression type of horizontal elevators has 
the advantage that no stuffingbox is needed for the piston 
rod, the water entering behind the piston only. The front 
end of the cylinder generally has a simple yoke through 
which the rod passes. 

When there is more than one elevator in a building, the 
cylinders are preferably mounted in pairs on top of each 
other; such a pair is then called a double-deck inucliliie, 
and this arrangement is shown in Fig. 14. 

3SS» Fast-Service C'oiiipi*ession-T,vpe Elevator. — Fig. 
15 is an illustration of an elevator machine of the compres- 
sion type built by the Otis Elevator Company, of Chicago 
(formerly the Crane Elevator Company). This machine 
is intended for fast passenger service and is therefore 



g 3',> ELEVATORS. 39 

fitted with a pilot valve P, involving the same principles as 
the Otis valve described in Arts. 19 and 20, and has an 
automatic stop-valve i". 

33. The pilot valve, main valve, and stop-valve are shown 
in detail in Fig. 16. The pilot, or auxiliary, valve is a slide 

valve; its seat has two ports a and b opening into pas- 
sages a' and b' of the main-valve casing. The passage a' 
leads into a space of the main valve behind a piston/, while 
the passage b' communicates with a chamber A in front of 
that piston, which chamber, in turn, is connected with the 
exhaust pipe R. Fijrs. 15 ;md Hi. Of the two other 
chambers A' and Tnf thi- main-valve I'asing, A' is connected 
to the supply pipe 1', and C to the cylinder by way of the 

//. S. 

yi ELEVAJriRS. § 3d 

\"a'.-*i >.. T'r.*: zr^^'.T. vi!vr '.' r*5iii5 of two single pistons and 
' r. T ^l .. :''/,': :> >t v r. : t h ^ i/i ^or* /. al read r men t ioned. the 
'V/y.'.*: y.<'.T. -7. ctA \r.^ pi-ston r. the latter beings of smaller 
o.arr.'rt'rr th'r ^.:h«?:r-. The valve chest of the pilot slide 
valve :s f' iZ.T.':^.\*'A "arith the S'jpply by a pipe J. 

Th*: *^/;yrra •.:'.' ' : :he valves is as follows: In the position 
'-'r.^rxn tr.*: vaiv*.-- ar-r at re<t, the pf»ri a being closed and the 
pr'---':r^ ''T. th*- r-i-t' r. '/ t* -wards the left (due to the differ- 
':r.' '- ir. arra -.f y ar.i ri. thus acting against a body of water 
f *t:.t\n*'A :n th»: >:^a' *r Vhind the piston/. If the pilot valve 
i> rri'»ve'l i'/-Aar'^:> th*: r:>^ht. it uncovers the prirt a and water 
;ji.'i»:r jir':-*'.ir*: enters the space fxrhind the piston /: the 
area of thi^ pi«*ton ^-Kring greater than the difference of the 
area> of y ari'l r, it moves towards the right, thus connecting 
the rhamr/«rr> -/ and C : that is. connecting the cylinder with 
th#: exhaii-.t. an'i hence the elevator car moves down. If the 
pilot valve \> moved from its neutral p^jsitionand to the left, 
the passa;re>// and h are connected: that is, the space behind 
the j/ir-ton /» i> put into rrimmunication with the exhaust. 
The exie>s pre>siire due t«> the difference of areas of q andr 
then rau>es the pistons to move to the left, opening com- 
muniration between the chambers B and C ; that is, it 
^onne^ts the < vlind*-r with the supply, and hence the eleva- 
tor r ar niove^ \\\). The sj^eed with which the main valve 
r^-porvN to tiie i^:lot valve is regulated by the valve j' in the 
-iipj^ly \}\\)*- A on on«: hand and furthermore by a screw ^ 
that ( an ]>*■ rnad«: to cnt'-r more or less into the passage b' by 
t ni nin;^ it from the outride. 

V'>r i\\i- >an;«: r'.ason that was j^iven in connection with 
' • ' ^M> pil-.t vaivf. Art. li>, the pilot valve must return 
"It '.iii.ii I. ;iil y t'. its inMitral position. The mechanism that 
.1' ' '>inpii-!i'-, tlii- is siniilar U) that used in the Otis valve. 
'I h' \.il\'- -t. ni n\ the })ilot valve is connected to the short 
.irni "\ a tw.-arinrd IcvrT A, which is pivoted at / to the 
''htial (i'.nhh- di^k-sliaped piece X of a sliding sleeve M. 
'ill'- l"ii;4 aim of the lever L is connected by means of a 
link M t«. the ^t<-ni ot' the main valve. The central piece ^V 
1 ' ' "Hiir M( <i al // with a one-arm lever 0, the shaft of which 

§ 39 ELEVATORS. 31 

is operated by a lever or sheave actuated by a shipper rope 
from the car. When the lever Q is thrown to the left, the 
sleeve M moves to the left, carrying the lever L and the 
pilot-valve stem with it, the point o' at which the link O 
connects with the main-valve stem being the pivotal point 
of the motion. As soon as the main valve commences to 
move to the left, that is, after the pilot valve is set by the 
shipper rope, the point / becomes the pivotal point, and the 
pilot valve is pulled back to its original position. Similar 
action takes place when the lever Q is moved towards the 

34, The action of the automatic stop-valve 5 is as 
follows: The valve has three pistons v, v\ and //, of which 
the first two serve to close the circular openings lead- 
ing from the inlet to the outlet. The piston ;/ is at all times 
actuated by whatever pressure there is on the cylinder, 
forcing it to the left and thus keeping the circular openings 
referred to open. The valve stem is connected by a lever 
and rod to a cam F^ Fig. 15, pivoted to the frame of the 
machine. This cam is ordinarily held, as shown in the 
illustration, between two rollers / and /' by means of a 
weight IV attached to it. The rollers / and /' are placed 
on a movable frame T guided horizontally as shown and 
called the tappet. On the guide rod / of this tappet are 
fastened the limit-stop buttons g^ g to the right and left, 
respectively, of a projection, or arm, // on the crosshead of 
the traveling sheaves. In either of the extreme positions of 
the crosshead, the arm // comes in contact with one of the 
buttons, pushing the tappet 7^ and thus operating the stop- 
valve and shutting off the communication between the main 
valve and cylinder. 

The valves v and v\ Fig. 10, are not fitted very closely, so 
that there is a certain small amount of leakage, which 
enables the valve to start back slowly as soon as the pilot 
valve and main valve are reversed ; as S(^on as the arm //, 
Fig. 15, leaves either of the buttons .i/- and g, the weight \V 
causes the valve to open quickly and wide. In case the 

32 ELEVATORS. § 39 

leakage around the valves v and v\ Fig. 16, proves too 
slight, a small direct pipe connection (not shown) is made 
between the middle chamber C of the main valve and the 
top of the cylinder at the closed end. This allows a small 
quantity of water, which is regulated by a stop- valve, to 
enter or leave the cylinder independently of the automatic 
valve 5 when the pilot valve is reversed so as to give the 
valve 5 the start. This pipe connection also serves the pur- 
pose of permitting the escape of air that may have accu- 
mulated in the cylinder. 

35, The hydraulic elevators described are by no means 
the only ones that are made or that are in operation. They 
are typical constructions, however, and a person will, if their 
principles are clearly understood, readily comprehend other 
designs as well. 



•$G, In cases where a natural water supply or a street 
main with sufficient pressure is available, the elevator may 
i)e directly connected with it. Such cases are rare, however, 
and therefore a pumping plant is almost always included 
in an elevator installation. This pumping plant consists 
usually of one or more pumps, a pressure tank, and a dis- 
cluirj^c tank suitably connected by piping provided with the 
necessary valves and other fixtures. 

•^7. A typical installation of an hydraulic elevator is 
sliown in Fi«;\ K. Tlie i)unip 7* takes the water from the 
(lischaii^e tank P and forces it into the pressure tank I\ 
whence* it enters the elevator c^ylinder ^through the supply 
pipe- .S. It leaves the elevator c^ylinder through the dis- 
charge pipe /, wliich carries it back to the discharge tank. 


I The waler is thus used over and over again; this is an 
important item where water rates are liigli. as is the case in 
most cities and towns. 


38. Since, with the usual arrangement of pumps, cylin- 
ders, and tanks, the pump may work continually while the 
cylinder takes a quantity of water out of the pressure tank 
only for every other {the up) trip of the car, the pump need 
be only large enough to supply the average quantity of water 
per unit of time, supposing the cars to be running continu- 
ously up and down. Since there is more or less interruption 
of traffic, the pumps will generally even then supply more 
water than is necessary and will have to be stopped and 
started frequently. For such intermittent service duplex 
steam pumps or electric pumps are most suitable and are, 
hence, generally used, although geared pumps, belt-driven 
pumps, and gas-engine power pumps are occasionally met 
with. ^^ 


39. Open tanks, formerly installed in great numbers on 
the roofs of buildings to furnish the necessary head, are 
gradually disappearing, and the closed pressure tank, as T. 
in Fig. 17, placed in the engine room, takes its place almost 
exclusively. Such closed pressure tanks are often placed at 
the top of the building also, thus utilizing both the natural 
head and the air pressure. In such a tank the required 
water pressure is obtained by having the tank partly filled 
with air and compressing the same by pumping in the 
water, so that it is really air pressure that gives to the water 
the necessary head. By leakage as well as by absorption in 
the water the quantity of air in the tank gradually grows 
less and must be renewed. In the smaller installations, such 
3s is shown in Fig. 17, the necessary air supply is obtained 
through a vent in the suction pipe of the water pump; in 
l^rge installations separate air pumps are provided fi 

§39 ELEVATORS. 35 


40. The pressurp used in ordinary closed-tank installa- 
tions ranges generally between 90 and 120 pounds per square 
inch. In some cases for high buildings these pressures 
have to be exceeded, and then hydraulic accumulators are 
installed instead of the pressure tanks. These high-pres- 
sure installations require also different designs of cylinders 
and other parts of the plant, but since there are but com- 
paratively few of these installations in operation we shall 
forego treating them in detail. 


41, Kinds of HtartinK Devices. — The stopping and 
starting of the pumps are effected automatically by various 
devices. In one kind of these devices the height of the 
water in the tank is made use of by means of a float to oper- 
ate the steam valve of a steam pump or the switch and 
rheostat of an electric pump; in another kind, the pressure 
in the tank is utilized to d« the same thing by means of a 
pressure valve. Floats are used only with open gravity 

42, Pressure-Regulated Htarting: Valve. — A device 
of the second of the above-named classes is shown in 
Fig. 17 at F. It consists of a pressure valve of much the 
same construction as a steam-boiler safety valve. It is con- 
nected to the pump discharge pipe or directly to the pres- 
sure tank by a small pipe/, into which is inserted a pressure 
gauge ^. The weighted lever of the valve V is connected 
to the throttle valve n of the steam pump by a rod r in such 
a manner that the throttle valve shuts off steam when the 
weight on the lever of the valve V is balanced by the 
required water pressure in the pressure tank, and opens to 
admit steam when the pressure falls below the required 
amount. A sight-feed oil cup o is generally placed in 
the steam pipe in advance of the throttle valve //, in order 


^ the prefe r vorking uf the same and to pre%'eot 

43L rtovd Unpilartiig^ VsItc. — In the device shown in 
P^. 18, tfar tvo Tatrvs I' and ■ spoken of in the previuDS 
uiide an: combined iato on«. 
TIbs device, which is largely tised 
ia cleratoT work and is manufac- 
Ioto) by lliomas P. Ford, of New 
Yorit, cuosists of a ^ring-actu- 
ated steani valve {' and a water 
piston I'rooving in a little cylin- 
der ll'nndcr the influence of lite 
water pressorc. It is easy lo see 
that by adjusting the spring 
pn^pedy the steam \-alve can be 
made to close when the water 
pressure on the piston /'exceeds 
a certain required amonnt. The 
rrgulattng valvesbouldbe placed 
in the steam supply pipe in a 
venical position between the 
■ r.-n chest and an ordinary valve. The oil cup 
M t>e placed so as to alkiW 
• ■il to pass through the 
T J i: l,i[ ing vah-e. The pipe 
■ -i.-i-iing the pressure tank 
:n ih*" pressure cylinder of 
'■dulaling valve shoukl be 
_] . i ii^'d with a globe valve and 

J .ini'in next to the valve, in 
order that the cap may easily 
be removed for repacking the 
hould be connected with the bottom 
e cylinder II' 

Fottl Rheostat Regulator. — A device much used 
with electric pumps and mauufactured by 

§ 39 ELEVATORS. 37 

Thomas P. Ford is illustrated in Fig. 13. The purpose of 
this apparatus is to obtain a comparatively large movement, 
which is necessary for operating the switch and rheostat of 
the electric motor. 

As in the apparatus shown in Fig. 18, the pressure pipe is 
connected to a small cylinder IT in which works a piston V 

against a weighted lever. This lever is. however, not con- 
nected directly to the stopping and starting arrangement, 
but to the piston of an auxiliary hydraulic valve ^I. This 
valve has an inlet connected to some constant water supply 
of moderate pres.sure {nut less than 35 pounds per square 
inch) and a discharge outlet. When the pressure in the 

38 ELEVATORS. f m 

lank falls below the required amount, the piston /"rises and 
carries with it the pistou of the anxiliary valve; water is 
then admitted into the cylinder Af of the main valve, caus- 
ing the piston R therein to be forced down and the outward 
end of a long double-armed lever L attached thereto to be 
furced up. This lever is also weighted and to it is attached 
the lever of a motor starling box. As soon as the pressure 
in the tank increases, the piston C moves down; by ilils 
movement the cylinder .1/is put in communication with the 
discharge, whereupon the main-valve piston moves up and 
the end of the lever L down by virtue of the weight attached 
to it. It is recommended in connecting up this valve to 
have the water from the constant supply go through 
raud-drum placed near the regulator before entering the 

45. Mason Elevator Pump-Pressure Ref^lator. 

Fig. 30 shows a regulating device much used in elevator work. 
Referring to the illustration, the operation is as follows: 
Steam from the boiler enters the regulator at the point 
marked "inlet" and passes through into the pump, which 
continues in motion until the required water pressure is 
obtained in the system, which acts through a J-inch pipe 
connected at n and upon the diaphragm D. This diaphragm 
is raised by the excess water pressure and carries with it 
the weighted lever L, opening the auxiliary valve A and 
admitting the water pressure from the connection b to the 
tup of the piston P, at the same time opening the exhaust 
port under the piston /', thus allowing the water under this 
piston to escape through the passage a' shown in dotted 
lines into the drip pipe {/, thereby pushing down the piston, 
which closes the steam valve and stops the pump. 

As soon as the pressure in the system is slightly reduced, 
the lever L. on account of the reduced pressure under the 
diaphragm, is forced down by the weights IC, carrying with- 
it the auxiliary valve A and thus opening the exhaust frofD'l 
the top of the piston, and at the same time admitting th&X 
water pressure under this piston, which is now forced \ 



and opens the steam valve, again starting the pump. This 
action is repeated as often as the pressure rises above and 
falls below the required amount. 

46, The Mason regulator is easily adapted for use in 
connection with a switch and rheostat for regulating elec- 
trically driven pumps. Fig. 21 shows such an arrangement 


■T-rAaS TA1.TV. 

47. Wbm tbe dcvxior scrriec is qmte contiowKis ami 
re^br it proves MlTsnUgeoits to many cases, especially 
with pomps diirtn efectrxally of by gas engines, tci have the 
pomp mn continnally an<l tbus 
to do away with the more or 
complicated auiomaiic- 
rait-e switch and rheostat ar- 
rangements. In such cases a 
by-pass TidTe is installed near 
the pump, which opens com- 
munication between the deliv- 
ery and suction pipes of the 
pumps whenever the pressure 
in the tank becomes excessive. 
DM^M — D«f/,f«rufip» By eIe\-ator men, such an ar- 
^3*^ ^ rangement is called a closed 


Pig. '23 is an illustration of 

the Furd by-pass valve. Its 

construction is similar to that 

Igulator described in Xx\. -14, and it is connected 

§ 39 ELEVATORS. 41 

up in the same manner, a mud-drum being preferably placed 
near the valve to free the water from any impurities before 
it enters the auxiliary valve. 


48. To provide for the emergency, should the regula- 
ting devices described in the previous articles stick, and 
should an excessive pressure accumulate in the tank, a 
pipe s fitted with a safety valve ;;/ (see Fig. 17) and lead- 
ing from the pressure tank to the discharge tank is generally 


49. Besides the fixtures already mentioned, there is pro- 
vided a water gauge w on the pressure tank and various 
globe valves ;/, ;/', and ;/", Fig. 17, which are used in start- 
ing and stopping the plant. 



60. Water. — The water to be used in hydraulic eleva- 
tors should be clear and free from sediment. It should 
enter the system through a strainer, so as to exclude all 
foreign matter likely to damage the valves and pistons. The 
water should be changed at least every three months and 
the whole system should then be cleaned by washing and 
flushing. This requires closing down the plant completely. 

61. Starting I'p and Running. — With all parts sup- 
posedly in good working order, joints tight, stuffingboxes, 
pistons, and valves properly packed, guides, sheaves, and 
other moving parts well oiled, start the pumps and partially 
fill the pressure tank; in doing so, the air in the tank will be 
compressed, but tluMc will not be sutfuient air in the tank 
to give the required i)rcssure. Therefore, when the tank is 


about half full of water, open the air vent in the suctiot 
pipe of the pump, thus introducing air with the water untilfl 
the proper pressure is reached, when the gauge shows abuuta 
one-ihird of air and two-thirds of water, this being the pro-1 
portion upon which tanks are generally based to amply suf>- 1 
ply the necessary amount of water for the cylinders. When I 
an extra air pump is provided, fill the tank two-thirds fiilii 
of water and supply the air pressure afterwards. The water I 
level indicated above should be carefully maintained by the 1 
engineer in charge during the operation of the plant by J 
opening the vent in the suction pipe of the pump occasion- 
ally or starting the air pumps, respectively, whenever the | 
water level rises higher through loss of air by leakage or I 
absorption. It is better tn have a little more air in the J 
tank than too little, since too small an air volume is apt tn J 
cause considerable fluctuation of the pressure during each i 
stroke of the elevator piston. 

After the necessary pressure has been reached, slowlyl 
open the stop-valve between the tank and the controlling^^ 
valve, which stop-valve is generally and preferably a gate 
valve. Ncjct, slowly open the controlling valve, all air valves 
or cocks having been previously opened, to allow the air con- 
tained in the cylinder to escape; the air cocks are shown 
at (T, Fig. C. and at b. Fig. 8. For the first filling of the 
cylinder, the controlling valve must be set for going up. 
After all the air is expelled, which can be ascertained by 
water running from the air cock into the funnel of the drip 
pipe in. Pigs. and S. close the air cock. The elevator is 
now ready for running. 

52. Absorption and UlHcliarge of Air.- — As already 
mentioned, the air will be absorbed by the water to a cer- 
tain extent. This air frees itself in the cylinder and may 
form a cushion. It is, therefore, occasionally necessary to 
remove the air. In vertical-cylinder (circulating) systems 
such an air cushion can form above and below the piston. 
Air below the piston is automatically removed in the Otis 
vertical elevator by a piston air valve r, Fig. (i, provided for 


the purpose, which lets the air into the space above the 
piston, whence it can be removed through the air cock a. 
When there is air in the cylinder, this will cause the car to 
spring up and down in stopping. When the quantity of air 
is small, it can generally be let out by opening the air cock 
and running a few trips. This should, therefore, be done 
occasionally. If there is much air in the cylinder the car 
must be run to the top and the controlling valve set for 
going d(Kcu, While the car and valve are in this position, 
open the air cock and allow the air to escape. This may 
have to be repeated several times before the air is all 
removed. If the absorption of the air by the water is 
found to be considerable, it may effectually be prevented by 
the introduction into the tank of a layer of heavy oil about 
4 inches thick. This expedient will, however, have to be 
resorted to but seldom. 

63. Settling: of Car. — After all the air is removed close 
the air cock, as otherwise the car will settle, that is, slowly 
creep down at the landings. If the air cock is properly 
closed and the car still shows a tendency to settle, the cause 
is probably that the piston or valve is leaking and needs 
repacking. Another cause for settling may be that the 
piston air valve c. Fig. G, does not properly seat. 

64. Groaning: Xolse In the Cylinder. — If a groaning 
noise is heard, it may be taken as a sign either that the two 
piston rods (in the vertical type) are not drawing alike or 
that the piston packing is worn out and needs renewal. If 
it is believed that the fault lies with the rods, this may be 
ascertained by trying to turn the rods with the hands; if 
one of them will turn, it needs tightening up. If the pack- 
ing is at fault, the car will settle. 

66. Stretching: of Cables. — The cables should not be 
allowed to stretch enough to prevent the car from reaching 
the top landing, because of the danger of the piston stri- 
king the bottom cylinder head. 

44 ELEVATORS. § 39 

56. Hand Cable, Iiimit-8top Buttons, Back-Stop 
Buttons. — The hand cable, or shipper rope, as we have 
called it, should be properly adjusted, neither too tight nor 
too loose. The limit-stop buttons should be so adjusted that 
the car will stop at a few inches beyond either extreme landing 
and before the piston strikes the head of the cylinder. The 
back-stop buttons should be so adjusted that the valve cannot 
be opened either way more than to give the car the required 
speed. In the case of auxiliary, or pilot, valves, the stops on 
the shipper sheave serve instead of the back-stop buttons. 

67. liUbricatlon. — The plungers in plunger elevators 
should be kept well greased and clean. A good way to 
clean and grease the plunger, suggested by the Plunger 
Elevator Company in connection with their ** elevator 
grease," is to stand at the bottom floor and to run the 
elevator slowly up while unping tJic plunger dry. On run- 
ning the car down again, cover the plunger with a thin coat 
of grease, rubbing it on and spreading it even with the 
hands. The plunger should be dry when the grease is 
applied; otherwise the grease will not stick. The inside of 
the cylinder should be lubricated about every two weeks with 
cylinder oil. Oil cups are generally provided for this pur- 
pose. The Otis Elevator Company, of Chicago (Crane Ele- 
vator Company), say the following in regard to lubrication: 
"The most effectual method of lubricating the internal 
parts of hydraulic-elevator plants, where pumps and tanks 
are used, is to carry the exhaust -steam drips from the foot 
of the pump-exhaust pipe to the discharge tank, thus saving 
the distilled water and cvlinder oil. This svstem is invalu- 
able when water holding minerals in solution is used, as 
these minerals greatly increase corrosion." 

Horizontal nuK^hines operated by city pressure are best 
lubricated witji a heavy grease, applied either mechanically 
or by means <»f a piece of waste on the end of a pole. The 
former method serves as a constant lubricator, while in the 
latter ease j^reasinj^ is often nej^^leeled and, ii\ consequence, 
packing lasts but a shc^'t time. 

§ 39 ELEVATORS. 45 

Mr. Ford recommends as a lubricant for his valves, 
described in Arts. 43, 44, and 47, common soap applied 
once a month. 

68. Bushing: Sheaves. — If the traveling-sheave bush- 
ing is worn so that the sheave binds or if the bushing is 
nearly worn through, turn it half around and thus obtain a 
new bearing. If it has been turned before, put in a new 

69. Precautions Ag^alnst Freezing. — Precaution must 
be taken against the water freezing in any part of the sys- 
tem. If the cvlinder and connections must be located in an 
exposed place, they should be protected against frost by 
building an air-tight box, open at the bottom, around them ; 
a small gas jet should be kept burning at the bottom, or 
when steam is available a coil should be placed near the 
cylinder. Plunger-elevator cylinders are exempt from the 
danger of freezing. Supply pipes outside of the building 
are best protected by burying them in the ground below the 
freezing line, say 6 feet. If this cannot be done, they 
should be covered with non-conducting material, the same 
as is used for steam pipes. If in cold weather the elevator 
service is to be stopped for any length of time the water 
must be drained off, care being taken that this is done 
thoroughly. This applies especially to small pipe connec- 
tions for drips, vents, etc., which should be free from bends, 
loops, or sags in which water may be left to freeze after the 
system has been drained. 

60. ClaslnK Do>vn Ilyclraulle Elevators. — We will 
imagine that for some purpose, as prevention of freezing, 
change of water, etc., the plant is to be closed down. After 
removing the lower limit-stop button, run the car slowly to 
the bottom. Next shut off the supply by closing the valve 
provided for the purpose in the supply pipe, as the v^alve ;/ 
in Fig. 17. In the plunger tyi)e of elevator machine, the 
valve and connections only are thus drained, the cylinder 
remaining full of water around the plunger, which, however, 

H. S, v.— 24 

46 ELEVATORS. §39 

does no harm, since being far underground the water will 
not freeze. In the horizontal machines, running the car 
down and closing the supply leaves both cylinder and 
valve free of water. In the vertical (circulating) machine, 
however, the cylinder and circulating pipe are still full of 
water when the car is down and must be drained. For this 
purpose, open the air cock and the drain-pipe valve //, Figs. 6 
and 8. Throw the valve for going up to empty the cylinder 
through the discharge pipe. Next throw the valve iov going 
doivn to empty the circulating pipe through the drain pipe. 
After all water is drained off, grease the cylinder with heavy 
grease if the machine is of the horizontal type, and grease 
the piston rods if of the vertical type. 

61. Packing Plnngrer and Piston Rods and Btuff- 
inccboxes. — Stuflingboxes that must be repacked from time 
to time occur in the plunger type, the vertical type, and the 
horizontal tension type of hydraulic elevators. For repack- 
ing the stuflingboxes, it is neither necessary nor expedient to 
drain the system. 

For packing plunger stuffingboxes, run up the car suffi- 
ciently to be enabled to work conveniently in the pit, shut 
the three-way controlling valve and the supply stop-valve 
between the tank and the controlling valve. Block up the 
car, then remove the j^^land of the stuffingbox and renew the 
packing; replace the gland, screwing up the bolts just tight 
enough to prevent leaking, open the supply stop-valve and 
then slowly the controlling valve, setting it for going up. 
Reiivjve the blocking. 

iVl. X'arioiis materials are used for packing plunger 
stiiH^iniihoxcs. I'^or the smaller sizes, such as sidewalk- 
el*- valor plungers, tii)rous packing, such as hemp, flax, or 
eolion, is used exelusively. For large plungers cup leathers 
are pr<)i)ai)ly the best packing. But since the cup-leather 
lint; must be sj)lit open in order to introduce it into the box, 
much ')f its value is impaired; therefore, fibrous packing is 
much used. 


63. To retain the cup-leathur principle anr! at the s 
time to avoid the objection to the butt joint, multiple 
leathers may be used. Fig. S3 
shows a plan that Is said to 
have proved very satisfactory. 
The packing consists of split 
leather rings, or even of ring 
sections, of V-shaped cross- 
section. The edges of these 
rings are cut down sharp, in 
consequence of which they act 
in much the same manner as 
cup leathers. The single sec- 
tions are, of course, intro- fig. 28, 

duced so as to break joints. This kind of packing is very 
tight, but is likely to create a great deal of friction. 

64. A much better arrangement is shown in Fig. 24. 
This packing, known as Wright's elevator packlug, con- 

sists of a split rubber ring / of cup-shaped cross-section and 
a split leather ring r of L-shaped section. Both rings are 
placed in the stufiingbox so as to break joints. 

6fi. For packing piston-rod stutfingboxes, close the sup- 
ply stop-valve and open the air cock to make sure that there 
is no pressure in the cylinder; remove the followers and 
glands of the stuffingboxes and renew the packing. Screw 
down the followers only light enough to prevent leaking. 
Fibrous packing is used exclusively. 


48 ELEVATORS. § 39 

66. Packing Vertical Cylinder Pistons. — In some 
designs of vertical elevators the piston can only be packed 
from the top, as in the elevators shown in Figs. 5 and 8. In 
others, provision is made for packing the piston either from 
the top or bottom, as in the Otis elevator shown in Fig. 0. 
In others, again, the piston can be packed only from the 
bottom, as in the elevator shown in Fig. 11. 

67. To pack a vertical cylinder piston from the top, run 
the car to the bottom and close the stop- valve in the supply 
pipe. Open the air cock at the head of the cylinder and also 
keep open the valve in the drain pipe from the side of the 
cylinder long enough to drain the water in the cylinder down 
to the level of the top of the piston. Now remove the top 
head of the cylinder, slipping it up the piston rod out of the 
way and fastening it there. If the piston is not near enough 
to the top of the cylinder to be accessible, attach a rope or 
small tackle to the 7Nain cables (not the counterbalance 
cables) a few feet above the car and draw them down suffi- 
ciently to bring the piston within reach. Remove the bolts 
in the piston follower by means of a socket wrench. Mark 
the exact position of the piston follower before removing it, 
so that there will be no difficulty in replacing it. 

In the elevators shown in Figs. 5 and 8 fibrous hemp pack- 
ing is used. In the design shown in Fig. 0, a combination of 
cup-leather and duck packing is used. On removing the 
follower of this piston, a leather cup / is found turned 
upwards, with coils // of -J-inch square duck packing on the 
outside. Tliis duck packing should be removed and the dirt 
c;leaneci out; also clean out the holes in the piston through 
which tlie water acts on the cup. If the leather cup is in 
good condition, replace it and on the outside place three 
new coils of JJ-incli s(|uare duck packing, being careful that 
they i)reak joints and also that the thickness of the three 
coils up and down does not fill the space by \ inch, as in 
sucli a case the water nii.i^ht swell the packing sufficiently to 
cranij) it in this space, thus desl roving its power to expand. 
\{ too tight, strip olY a tew thicknesses of canvas. 

§ :V.> ELEVATORS. 49 

Replace the piston follower and let the piston down to its 
right position. Replace the cylinder head and gradually 
open the gate valve in the supply pipe, first being sure that 
the operating valve is on the center. As soon as the air has 
escaped, close the air cock and the elevator is ready to run. 

68. To pack vertical-cylinder pistons from the bottom, 
remove the top limit-stop button and run the car up until 
the piston strikes the bottom head of the cylinder. Secure 
the car in this position by passing a strong rope under the 
girdle, or crosshead, and over the sheave timbers. When 
secured, close the gate valve in the supply pipe, open the air 
cock at the head of the cylinder, and throw the controlling 
valve for the car to go up. Also open the valve in the drain 
pipe from the side of the cylinder and from the lower head of 
the cylinder, thus allowing the water to drain out of the 
cylinder. When the cylinder is empty, throw the valve for 
the car to descend^ in order to drain the water from the 
circulating pipe. 

In cases of tank pressure, where the level of water in the 
lower tank is above the bottom of the cylinder, the gate valve 
in the discharge pipe will have to be closed as soon as the 
water in the cylinder is on the level with that in the tank, 
allowing the rest to pass through the drain pipe to the sewer. 
When all water is drained off, proceed as directed in the 
previous article in renewing the packing. To refill the cyl- 
inder after packing, close the valves in the drain pipes, leave 
open the air cock at the head of the cylinder, leave the con- 
trolling valve in the position to descend, and open the gate 
valve in the discharge. Slowly open the gate valve in the 
supply pipe, allowing the cylinder to fill gradually and the air 
to escape at the head of the cylinder. When the cylinder is 
full of water, close the air cock and put the controlling valve 
on the center. The car can then be untied, the limit-stop 
button reset, and the elevator is ready to use. 

69. Packings Horizontal Hydraulic Elevators. — In a 

compression-type elevator run the car to within 1 foot of 
the extreme top and secure it to the overhead beams with a 



chain or rope. Close the gate valves in the supply and d 
charge pipes and open the air cock and valve in the dra 
pipe, emptying the cylinder. Remove the buffer across t 
front (open) end of the cylinder and shde it along tiie pistcml 
rod out of the way. Remove the follower of the piston, i 
With a hooked piece of wire remove the old packing. Ra 
the piston head until it is in the center of the cylinder, 
the cylinder is fonnd to be in good condition, cut off fouR 
rings of square lubricated fibrous packing 9 inches longerfl 
than the circumference of the cylinder. Place the two ends ' 
of n ring together and form tucks with the balance. Force 
in these tucks one at a time with a hardwood stick until all 
are level against the head. Proceed in the same manner 
with the remainder of the packing. Arrange the packing sod 
that the joints in the different rings do not come together. X 

If the cylinder is badly worn, use square pure-rubber I 
packing for the first and last ring, and make these but I inchjl 
larger than the circumference of the cylinder. This rubber 1 
insures a backing for the fibrous packing. After puttin^l 
the packing in position, replace the follower and screw qoM 
the nuts with the fingers until the follower is close to theT 
packing, On two of the studs opposite each other will bel 
found jam nuts. Set these out against the follower andl 
tighten with a wrench. Replace the buffer. Close the drain I 
valve and set the controlling valve for going up. Open the J 
gate valve in the supply pipe and fill the cylinder. When.l 
the cylinder is filled, close the air cock. As the car in the! 
first place was not at the extreme top, the pressure in th«l 
cylinder will run the piston head against the buffer and] 
the car will ascend to the extreme top. The fastenings may* 
then be removed. Throw the controlling valve on the centei^ 
and open the discharge. The elevator is then ready to- 
descend. Do not make any trips until the cylinder 
thoroughly greased. Continue greasing twice a week. 

In the course of time, leaks will occur in the cylinder,] 
Loosen the jam nuts back of the follower and set up lh«H 
mils on the studs equally until the leak is stopped. Thenj 
retighten the jam mils. 

§ 39 ELEVATORvS. 51 

70. In the tension type of horizontal hydraulic elevator, 
the procedure is exactly the same, with the exception that 
there is no buffer to be removed, the open end of the cylin- 
der being at the back. 

71. Fackin^c the Controlling Valves. — Run the car 

to the bottom, close the supply valve, and drain the system 
as previously described. When the water is all drained off 
take off the cap. After marking the exact position of the 
various parts in relation to one another, remove the valve 
proper and renew the packings, placing the new ones in the 
same position as the old ones. Before refilling the cylinder 
close the valves in the drain pipes, but leave the air cock at 
the head of the cylinder open and be careful that the valve 
is in the position for the car to go down. Gradually open 
the gate valve in the supply pipe. When the cylinder is 
filled, close the air cock and open the gate in the discharge 

72. Fackincc Material. — Fibrous packing is furnished 
by the trade in the form of a square braided fiber impreg- 
nated with a greasy substance. The material used is hemp, 
flax, or cotton. It is claimed by some that cotton is a more 
suitable material, being more elastic, softer, and more 
absorbent for grease. In using it, it is important that it 
should be well soaked in boiling tallow for several hours to 
exclude with certainty all air from the pores. 

73. Leather for cups should be of the best quality, of 
an even thickness, free from blemish, and treated with a 
waterproof dressing. The cups should be of sufficient stiff- 
ness to be self-sustaining when passing over the perforated 
valve lining. Elevator builders generally make and furnish 
packings to fit their machinery, and it is recommended to 
get supplies from them. When ordering cups, the pressure 
of water carried should be specified, as the stiff cups 
intended for high pressure would not set out against the 
valve lining when low pressure is used. 



(PART 4.) 



1. The term car safeties applies to safety devices that 
in cases of emergency prevent the car from falling unre- 
tarded to the bottom of the shaft. All these devices, with 
the exception of air cushions, consist primarily of catches in 
the shape of wedges, pawls, etc. that lock the car to the 
guides. They differ, however, in the means by which these 
catches are set in operation. In some designs of car safeties, 
only the breaking of the hoisting cable or cables or its 
becoming slack through a temporary sticking of the car 
in its descent will operate the safety catches. In other 
designs, excessive speed of the car is relied on to operate 


S. Fig. 1 shows the simplest form of a car safety 
intended to operate at the breaking of the hoisting cable or 
its becoming slack through a temporary arrest of the car. 
The hoisting cable is attached to a bolt /% which is free to 
slide in its hole in d^ but has an enlarged head on the bottom 
through which the curved spring e passes. The lower end c 


For notice of copyrij^ht, see page immediately following the title f>age. 



of the bolt is slotted to receive one end of the bell-crank 
levers E, E, which are pivoted to the uprights of the car. 
The other ends of the bell-crank levers carry pawls /, /, 
which are spring-actuated and adapted to enter between 
suitable ratchet teeth on the guides. The pawls are nor- 
mally held out of en- 
gagement with the 
teeth, the spring e 
being compressed by 
the load. Should the 
cable break or be- 
come slack for any 
reason, such as a tem- 
porary arrest of the 
car in its descent, the 
tension in the springs 
would be relieved and 
the pawls would con- 
sequently engage the 
ratchet teeth, pre- 
venting the car from 

3. P a w I - a n d - 
ratchet arrange- 
ments, such as are 
shown typically in 
Fig. 1, are now but 
seldom used ; they are 
suitable only for slow 
generally replaced by a wedge that 
k-s and the ^uide shoes. Fig. % is an 
of this kind. The cable is attached, 
to a spring-actuated bolt or stirrup F 
I'late \, to which the links i, L are 
urn. are connected to levers E, E. 
the helical springs surrounding the 
.1- down thf ])l;Ue A", lifting up the 

n S-sl 



outer ends of the levers E^ E. These levers, in turn, then 
press on serrated wedges Wy I'T contained in pockets of the 
guide shoes in such a manner that ordinarily they remain 

by gravity out of contact with the guides. The pressure of 
the lever ends forces them against the guides and the down- 
ward motion of the falling car wedges them tight, the 


n their 
=f with 

serrations or teeth bury- 
ing themselves into the 
wood of the guides. 
When the car is again 
lifted, the wedges disen- 
gitge themselves. This 
safety is regularly used 
l>y the A. B. See Manu- 
facturing Company on 
freight elevators 
ooden guides. 

4. It will be noticed in 
the arrangement shown 
in Fig. a that two cables 
are used, but in order 
that the safety mecha- 
nism should operate, both 
cables must break or 
become slack at the same 

5. In order to make 
the safety device respond 
to the breaking, slacking, 
or even stretching of one 
of several cables used, the 
cables must be independ- 
ently attached to wedge- 
operating levers. Figs, ii 
and 4 show an arrange- 
ment of this kind known 
as tlie Otis Ki*avlty- 
^vwljeo safety. It con- 
sists of a so-called safety 
plank /' of hardwo<.d 
placfd under the plat- 
form of the car, and into 
the ends of which are let 


the guide shoes, each of which consists of a fixed jaw Cai 
an adjustable one D, the latter being very clearly showi 
in Fig. 4 (a) and [b). Between the fixed jaw and 
guide A is inserted a wedge (!', which is normally held b 
gravity in such a position that the shoe can slide freeljj 
over the guide. The cables are attached, in the i 
shown in Fig. 3, to the Hliackle rods F, Fig. 4, whicl 
in turn, pass through an e<]iializliiK lever G pivoted in A 
suitable manner to the safety plank P. From the shackl 
rods the cables are carried upwards over rollers i 
wroughi-iron girdle /?, Fig. 3, at the top of the car. 
virtue of the equalizing levers, each of the four cables car^fl 
ries an equal strain, and as long as all cables are equal 
sound the equalizing levers will remain in their origim 
position, that is, horizontal, as shown in Fig. 4 {a). 
soon, however, as one of the cables breaks or even stretchi 
more than its neighbor, the equalizing lever will tilt, as ' 
shown in Fig. 4 {b). An arm / of the equalizing lever car- 
ries a setscrew s, which is so adjusted that when the lever 
tills down it will strike the end of a finger H mounted on 
a shaft under the safety plank. This finger then presses 
against the wedge W, making it engage the guide. Another 
setscrew s' is provided on the arm of the equalizing lever 
and has the same effect on the finger H in case the lever 
tilts the other way. It is thus seen that in case any of the 
cables become, slack, stretched, or broken, the car will be 
stopped. The car may then be lifted by the other cable^fl 
but it cannot be lowered until the damaged cable is replacedj 
The spring .S acting on the spring plate i" keeps the wedgl 
W in place and prevents it, under normal conditions, frt 
being drawn into engagement by mere sliding contact witi 
the guide, 


6. Safeties operated by the breakage, slacking, or stretcl 
ing of a hoisting cable are today not considered sufficiei 
except for very slow-speed elevators. In all high-s 
elevators the catches are set into operation by < 

§ 40 ELEVATORS. 7 

speed of the car, and the most generally adopted plan to 
effect this is the employment of a centrifugal governor 
placed either on top of the hoistway or carried on the car, 
and operated by an endless rope attached to the car or 
some fixed point. Such an arrangement is often found in 
addition to safeties to be operated by breaking cables, 
notably when city ordinances demand the latter. 

7. An example of such a safety device is given in the 
Otis elevator shown in Fig. 3. The finger shaft mentioned 
in Art. 6 can also be operated by a rope r attached to a 
lever /, which, in turn, presses on a finger / on the finger 
shaft. The rope r passes around the pulley of a centrifugal 
governor C, Fig. 3, on top of the hoistway and an idler at the 
bottom. The idler is mounted on a crosshead that slides 
vertically in short guides and is weighted so as to give the 
rope r the proper tension. The centrifugal governor, by the 
outward motion of the balls, operates a clutch consisting of 
two eccentrics g and ^', between which the rope r passes and 
which are geared together so as to grasp and pinch the rope 
when the balls move out too far, owing to excessive speed. 
The shaft of the eccentric^' has a crank o conaected by a 
rod to the operating lever of the ball governor G. The 
eccentric^' is, however, loose on its shaft and has fastened 
to it an arm a having a stop pin /, against which the crank o 
strikes at excessive speed of the governor, bringing the 
eccentrics together so as to just bite the rope r. The con- 
tinuing motion of the rope then pulls the eccentrics over 
fully, finishing the grip. The governor thus only starts the 
gripping of the eccentrics. It will be easily understood that 
reversing the motion of the car will throw the eccentrics 
back into their original position. The gripping of the rope 
causes the descending car to turn the lever / left-handed; 
this, in turn, rotates the finger shaft through engaging the 
finger/*, and the finger //then operates the wedge \V\ the 
guides are thus gripped. 

8. Another governor-operated device that is extensively 
used by the Otis Elevator Company in connection with steel 



guides is shown, together with the whole car frame, in Fig. 5, 
and in detail in Fig. 0. It will be noticed from the drawing 
that the four hoisting cables are not connected in any way 


' ' "~ - "- -^tt* ^ => ^v^N.-^-A'#l^ -"-"""' ' " 


Fig. 5. 

with the saft^ty device, but that the latter is solely operated 
l)y the governor rope. The rope is attached to a lever Z, 
whirh is fastened to a shaft .V running across the top of the car 
frame. This shaft is held, nornially, in a fixed position by 
a helical si)rini^ .9 and a stop-collar, or dog, ^/, resting against 
the guide-shoe casting. A little nearer the fulcrum of the 

§ 40 ELEVATORS. 9 

lever L a rod r is attached to this lever; and to a separate 
lever / on the other end of the shaft 5 a similar rod r' is 
attached. These rods extend downwards to the safety plank, 
where they have flattened ends c. Figs. 5 and C. A slot in 
each of these flattened ends serves to guide the rods by 
means of a pin/. On the under side of the flattened end is 
a shelf /, Fig. 6, that supports a loose roller r, serrated on 

its cylindrical surface and contained in a pocket formed in 
the casting on the end of the safety plank. This pocket 
is so formed that if the roller r be lifted, it will be wedged 
in between the back wall of the pocket and the side of the 
T-shaped guide rail. The operation of this arrangement 
will be easily understood from the above brief description 
and Fig. 6, which shows the clamping roller in action and 
out of action. 

9. In some'governor-operated safeties the governor is 
carried under the platform of the car. Fig. 7 shows an 
arrangement of this kind as built by the A. B. See Man- 
ufacturing Company, and is intended for use with steel 
guides. Fig. 7 («) is a bottom view, while Fig. 7 {b) is an 

H. S. V.-25 

§40 ELEVATORS. 11 

elevation of the governor and cable-gripping device. To 
the guide-shoe castings 5, shown in side view in Fig. 7 (r), 
shown complete at the left of Fig. 7 (r?), and at the right 
with the guide shoe proper and its sleeve removed, are piv- 
oted the levers Z, L and L\ L'. The short arms of these 
levers carry grip blocks B^ B and B\ B\ which are intended 
to close upon the guide rails in case of excessive speed. 
The long arms of the levers Z, L' carry rollers r, r. Each 
pair of levers is connected by a spring s that normally holds 
the grip blocks off the guide rail. The governor rope x 
passes up from the bottom of the elevator shaft over the 
governor sheave H to the first one of a set of sheaves 
mounted in a crosshead C\ thence to the first one of another 
similar set of sheaves mounted in a crosshead C\ thence 
back and forth over the other sheaves of these sets, and 
finally over an idler D up to the top of the hoistway. The 
crossheads C and C are properly guided and held by springs 
a certain extreme distance apart under normal conditions. 
To the crossheads are bolted cast-iron wedges W, \V\ which 
are so designed as to enter between the rollers r, r on 
the ends of the long arms of the levers Z, L\ and thus to 
push the same apart, closing the grip blocks down on the 
guide rails. These wedges enter between the rollers when 
the governor rope is arrested by the gripping device on the 
governor, since then the two sets of sheaves mounted on the 
crossheads C, C will be pulled together by the rope short- 
ening between them. 

10. The action of the governor will be easily understood 
from Fig. 7 {b). The governor rope x coming from the 
governor sheave // passes between two jaws j and j\ the 
former of which is pivoted to the governor frame and is 
actuated by a helical spring / that gives it a tendency to 
bear down on the rope against the other jaw y, which is 
fixed. The movable jawy has an arm a attached to it, over 
which hooks the lug / on one end of a double-armed lever 
or finger /. The other end of the lever f projects into 
the paths of the governor weights ic, 7U so as to be struck 



by them when ihey Ry out too much, owing to exc 
speed. In this case the lug / releases the jaw/, the rope x ] 
is locked to the frame, and the safety 1 
J — I is put into action. 




9AFETV imfM. 

II. Fig. H is a diagram of an 
arrangement often met with on Otis ' 
steam elevators. A so-called safety { 
drum S is placed on the same shaft [ 
as the overhead sheave // fur the J 
hoisting rope. Attached to this safety I 
drum are two ropes; one, the safety j 
rope s, runs down to the levers of a ] 
suitable car safety on the car, and 
the other one. /, which is wound the 
reverse way on the drum, runs down 
to the hoisting drum; this rope is 
I illtd the take-up rope. When the 
I II is ascending, the take-up rope ] 
nnids the safety rope on the drum i'. , 
If the hoisting cable C should break, 
the weight of the car would come on J 
the safety rope and thus throw the I 
car safety into action. The hoistings I 
rope is generally also connected tol 
an independent car safety. 

t2. In connection with the safety I 

drum, a governor-cont rolled brake | 

^"'- •*■ is generally used, which, if the hoist*' 

ing rope should break, insures a gradual fall of the car, J 

thus giving the safety time to act without a sudden shock. 

The governor and brake are shown in diagrammatic form J 
in Fig. 1». where S is the safety drum, // the brake pulley, I 
and C a spur gear driving a. pinion /* From the shaft of J 
this pinion motion is transmitted to the governor spindle by J 

§40 ELEVATORS, 13 

bevel gears, as shown. The sleeve of the governor operates 
a bell-crank lever L having a projection /, on which is sup- 
ported, by a hook h, the brake lever W. It is easy to see 

that when the governor balls fly out owing to the excess- 
ive speed of the car, the arm / will pass from under the 
hook h, and the weight on the brake lever IF will apply the 
band brake. 

13. The different designs of car safeties in actual use 
are very numerous, but a person understanding the oper- 
ation of those here described will be able to understand the 
operation of most of them. 


14, The importance of keeping car safeties and guides 
clean and well lubricated, so that they will promptly do 
their duty when called upon, cannot be emphasized too 
strongly. Car safeties need adjustment from time to time. 

14 ELEVATORS. §40 

15, When the guide shoes are adjustable, as most of 
them are, they should be so adjusted that the car will not 
wabble, but they should not be tight enough to bind on the 
guide rails. With spring-actuated guide shoes, such as are 
shown in Fig. T (f), for instance, the proper adjustment is 
easily acci>niplished by manipulating the screw bolts u in 
the same manner as the bolts of a stuffingbox. 

In the Otis wedge safety shown in Fig. 4, the spring 5 
must be just tight enough to prevent the wedge Jr being 
pulled upwards when the car is descending by the guide 
rail -/ coming in contact with it. A weakness of the 
spring ^S' frequently causes wedges to rattle. The wedge 
should move perfectly free and should l)e frequently exam- 
ined to see that it does. If, when the safety wedges move 
freely and the springs .S' are sufficiently tight, the wedges 
are still thrown into action or rattle when the car descends, 
the probability is that one of the cables has stretched or is 
broken. Care must be taken that all cables draw alike; 
when they do, the equalizing lever G should be horizontal, 
as shown in Fig. 4 (</). In this position the setscrews s, s' 
should not touch the finger H, but should be so adjusted as 
to touch and move the finger when the lever G is tipped a 
certain amount either way. The governor should not be 
too sensitive to harmless variations in car speed. For this 
reason, the governor r<»pe r acts on the lever / through the 
intermediary of a spriiivi:. as shown in Fig. 3. This spring 
should be just tii^ht eiiou-^h to prevent the wedges from 
rattling when the car is moving at its normal s[>eed, but not 
tighter, or the usefiihiess of the governor will be destroyed. 

1(J. Guides should not be allowed to become gummy, 

for in this oon(li:i..n they are apt to cause much trouble; 
they frequently cause the safety wedges to stick, to be 
thrown into action unnecessarily, or, at least, to rattle. The 
goveruf'jr should be examined frecjuently. 

17. In case the safety has acted and has stopped the 
car, it is of the greatest impc»rtance to see, before unlocking 
the safety, that there is no slack in the hoisting cable. If 

§40 ELEVATORS. 15 

there is slack, carefully take it up very slowly, reversing the 
motion of the motor and running it slowly. In hydraulic 
elevators, this can be done generally by carefully opening 
the controlling valve; in electric elevators, it is better to 
turn the worm-shaft by hand. After the slack has been 
taken up, unlock the safety catches. Most safeties are so 
arranged that they unlock automatically when the car is 
moved upwards. Thus, in the Otis gravity-wedge safety 
the wedges will drop back by gravity. In the safety shown 
in Fig. 5, the grip roller will readjust itself. In the safety 
shown in Fig. 7, the governor rope will automatically release 
itself when the car is going up, but the tripping device 
must be readjusted by hand. A hole in the car floor is pro- 
vided for that purpose. 

In case the car has been stopped above the top landing, it 
may become necessary to remove the limit-stop button on 
the shipper rope, so that the car may be raised high enough 
to unlock it. If this should prove insufficient, it may even 
become necessary to raise the car by a tackle. 


18. The car safeties treated in Arts. 2 to 17 are 
designed to act immediately after the slacking or the break- 
ing of a cable, or at the attainment of an excessive car 
speed. If, when the cable breaks, the car safety should fail 
to work, owing to neglect or some other cause, the car will 
drop unretarded to the bottom of the hoistway, causing 
destruction of property and the probable death of the pas- 
sengers. An always-ready means of preventing such serious 
accidents is the air cushion. This may be formed by 
extending the hoistway below the lowest landing in the 
form of a pit, which has a cross-section at its top somewhat 
larger than the platform of the car and which gradually 
tapers towards the bottom to nearly the same cross-section 
as the platform. When the car falls into this pit, the air 
within it is compressed and is forced out gradually around 
the platform of the car, thus letting the car down gradually. 

10 ELEVATORS. § 40 

19. Air-cushion pits, in order to be effective, should 
have a depth equal to one-fifth the whole lift of the car, 
that is, 20 feet for each 100 feet of hoist way. The walls of 
the pit must be air-tight, and great care must be used in 
their construction. Owing to local conditions, it is not 
always possible to extend the pit far enough below the 
ground to make it efficient, in which case it may be formed 
by making the lower part of the hoistway air-tight, say for 
one or two stories, and providing it with air-tight doors. 
The engineer in charge of the plant can only see that the 
pit is not filled with rubbish and when there any doors that 
they close air-tight. 




20. The question of elevator enelosures is largely a 
matter of city ordinances. In general, it may be said that 
every i)()ssil)le means should be taken to prevent accident to 
I>asseiigers on Uu- elevator, as well as persons whose duty 
brings them near elevator shafts and hatchways. What- 
ever means are taken ])v the builders, either of their own 
acH-ounl or in eoini)lian( c with city ordinances, it is the duty 
ot the engineer in charj^e to see to it that all enclosures are 
kept in j)r«)j)er cnndition. }lv, should be constantly on the 
lookout t<»r inij)r«)\cinents in this line. 

\\ Ik never possible, elevator enelosures should extend 
troni lloor to (-eiliiiM, to j)revent anything that is being car- 
ried on the ear eatehinj;- between its platform and the ceil- 
ing. No j)rojeeti<>n^ whatever should extend into the 
hoistway. It lull enclosures are not practicable and goods 
are carrieil that are liable to stick out, such as rods and sim- 
ilar articles, a car should be tised that is enclosed on at 

least t hree sides. 

g 40 ELEVATORS. 17 

Full enclosures need not necessarily be solid walls or par- 
titions, but can be made of lattice, or grille, work substan- 
tially braced. As a matter of fact, solid walls for elevator 
shafts, while recommended by some engineers, are of doubt- 
ful value. An elevator shaft so constructed will act, in case 
of fire, as a chimney, and will carry the flames from one 
floor to another. Besides, such shafts are apt to be dark 
unless windows are arranged in them, which make the shaft 
more dangerous in case of fire. The windows in such shafts 
should be securely fastened and preferably covered with 
wire screens. Latticework enclosures will admit plenty of 
light. In case enclosures are not carried up to the ceiling, 
they should be at least 5 feet high. Many an accident has 
occurred by people bending over too low enclosures to look 
for the car, which then struck them while coming down. 
Passenger-elevator enclosures are usually made of artistically 
formed wrought iron and are intended as an ornament to 
the building in addition to their usefulness. They are gen- 
erally expensively varnished and should, therefore, be 
treated with care. They should be cleaned with a feather 
duster and soft rags. The use of gritty substances, soap, 
or oil should be avoided. They should be revarnished from 
time to time, especially after repairs have been made. 


21. Requirements. — Elevator doors should always be, 
if possible, sliding doors or gates so hung that they will 
operate very freely. They should be provided with latches 
or locks that can be opened only from the inside of the shaft, 
but they should open easily; that is, without requiring 
much exertion on the part of the operator. Self-closing 
doors are to be preferred. The operator should not, however, 
rely on these self-closing devices, but should always make 
sure that the door is closed before he leaves the landing 
with his car. He will and should be held strictly responsi- 
ble for accidents due to doors having been left open. 

§ 40 ELEVATORS. 19 

22. Self-Openingr and Self-Closing Elevator Doors. 

Various devices are used by different manufacturers to 
make an elevator door self-opening and self-closing. These 
devices, in general, have for their object the automatic 
closing and locking of the door immediately upon the eleva- 
tor car leaving a landing, and, in addition, are so designed 
that the operator can open or close the door at will without 
touching it while the car is at one of its landings and at rest. 

23. The elevator-door operating device made by the 
Winslow Brothers Company, Chicago, Illinois, is shown in 
Fig. 10. The operation of this device is purely mechanical, 
the door being moved either way by a friction cone engaging 
either side of a suitable bar rigidly connected to the door. 
The construction of the device is as follows: The door a is 
supported by rollers b, b upon a level track c having a 
V groove planed in it to receive the V-shaped rollers. This 
arrangement prevents any side motion of the door. The 
so-called traction plane d is rigidly attached to the two 
door hangers that carry the rollers. A vertical shaft e car- 
rying a friction cone/" and also a cone-operating device at 
the top of each landing extends from the top to the bottom 
of the elevator shaft and is continually revolved by a small 
electric motor, or from some other source of power by 
belting. The so-called swing bar g is pivoted to a bracket // 
that is rigidly fastened to the transom above the door; the 
swing bar carries a bushing so fitted as to allow it to swing 
a little. The revolving shaft r, which owing to its length is 
quite flexible, passes through the bushing of the swing bar, 
the said bushing forming a journal for the shaft. The free 
end of the swing bar carries the adjustable buffer / intended 
to come in contact with a vertical shoe placed on top of the 
car. This vertical shoe can be thrown forwards so as to 
press against the buffer, and hence can be made to swing 
the swing bar around its pivot by a treadle in the car 
operated by the foot of the operator. 

The traction plane is slotted, the slot being beveled and 
wider at the bottom ; by pressing the buffer / away from the 


le side of thei^H 

tf-hnff ^ill thlli; ^^™ 


car the Mctioa cooe will be pressed gainst the 

slot nearest the uaBsom and the revolving cone will tbus 

open the door. 

As soon as the operator removes his foot from the treadle, 
the shoe on the top of the car will move away from the 
buffer /' and the shaft will spring back, bringing tbe friction 
cone against that side of the slot in the traction plane that 
is farthest from the transom; the revolving cone will then, 
by its friction against the surface with which it engages, 
cause the dnor to close. 

As has just been explained, the door closes whenever the 
shoe on the top of the car is moved out of contact with the 
buffer/. This shoe is quite short; consequently, should 
the operator forget to remove his foot from the treadle in 
the car when starting the elevator, the movement of the car 
will very quickly take the shoe vertically out of engagement 
with the buffer r; the revolving shaft ^ will then immedi' 
atcly spring back to its normal position and the door will 
closed automatically. 

The door is held open automatically while the car is at a 
landing by virtue of a recess in the end of the traction plane 
into which the friction cone passes after opening the door. 
The door after closing is locked automatically by a catch i. 

34. The Burdett-Rowntree Manufacturing Company u 
a horizontal pneumatic ram at each landing to automati-1 
cally open and close the door. The piston of the ram i 
attached by a link to a long swinging lever connected to the.l 
door, and as the ram piston moves one way or the other ill 
carries the door with it. The device is so designed that thi 
door is always held closed until the car is at a landing, whei 
the operator, by pressing on a treadle, throws a movable 
vertical shoe against a suitable part of the valve gear.l 
This operation unlocks the door and admits air i 
sure tfi one side of the piston in the ram cylinder, at thel 
same time opening the other side to the exhaust. The door I 
now opens, and when wide open can be kept so by a finger I 
lock as long as the car is at rest. Whenever the operator 1 


§ 40 ELEVATORS. 21 

removes his foot from the treadle, or unlocks the finger 
lock, or starts the car either way without having closed the 
door, the door closes automatically by reason of the valve 
gear operated by the shoe on the car returning immediately 
to its normal position. 

35. Car-IiOcklngf Device. — With elevator doors that 
are operated directly by hand by the operator, a ear-lockin|? 
device is sometimes used that automatically holds the car in 
position at its landings and only releases the car when the 
door is fully closed. While such devices are called car- 
locking devices, it must not be inferred that they lock the car 
itself to the landings or to the guides; instead they lock the 
operating device in the car so that the operator cannot 
move it to start the car in case the door has been left open. 

26. Fig. 11 shows the car-locking device designed by 
Messrs. I. S. Muckle and W. H. B. Teamen In Fig. 11 (a), 
the car A is shown at one of its landings and at rest, in 
which position the operating device F occupies its central 
position. The door D is unlatched and opened, as shown in 
Fig. 11 (d) and (c) ; the operating device in the car is then 

The following description of the device is partially taken 
from the patent specifications: Secured to one of the floor- 
beams within the elevator well is a spring latch E, which is 
bent as shown in Fig. 11 (rt), and extends up into the path 
of an arm d secured to the door D. This arm is notched 
at d^ to receive the spring latch E when the door is closed. 
When the latch is in the notch of the arm of the door, the 
latter cannot be moved until the latch is pushed out of the 
notch by the mechanism carried by the car; the door will 
then be free to be opened. 

A pinion /^ is keyed to the shaft /", of the operating device 
in the car and meshes with a gear/, turning on the stud/. 
A crankpin on this gear / is connected by a rod / to the 
lever/ pivoted at/ to a bracket a^ fastened to the bottom 
of the car. A bearing a on the bottom of the car carries a 

g 40 ELEVATORS. 23 

slide Aj, and this slide is connected to the levery, by a rod rt,. 
It is readily seen that, by virtue of the manner in which the 
parts are connected, the slide A, will be in its extreme outer 
position when the operating device is in its central position, 
as shown in Fig. 11 (a). The slide ,(, carries a roller (i, that 
engages with the spring latch E and forces it out of the 
notch (/, of the arm rf carried by the sliding door, releasing 
the latter. 

It is seen from the above description that the combination 
of the slide A^ with the operating device constitutes a mech- 
anism adapted to release the sliding door whenever the 
operating device is moved to stop the car, that is, is moved 
to its central position. 

It will now be shown how the operating device is rendered 
inoperative, i, e., how the operator is prevented from start- 
ing the car while the door is open. On the face of the 
elevator well, to one side of the spring latch £, is a plate G 
carrying a stud ^ on which is hung a three-armed lever. 
The arm^, of this lever extends in the path of an arm rf, 
depending from the door, so that the opening of the door 
allows the lever, under the influence of the weight ^„ to turn 
to the position shown in Fig. II {d). In this position the 
arm/', of the lever has passed behind a flange <7, of the slide j4, 
and prevents the slide from being drawn towards the car. 
Consequently, the operator cannot move his operating device 
to start the car. since this can only be moved when the slide v4, 
is free. On tlosing the door, the dependent arm i/, of the 
<loor engages the arm /, and turning the lever about its 
fulcrum X' moves the arm ^, out of the way of the flange 
on Ay, thus unlocking the slide and hence the operating 


many instances it is impractical to erect enclosures 
id, as. for instance, when the elevator is located in 
B warehouse and must be aci^essible from all 
b RCase, the holes in the floors through which 


the car passes must be kept covered and must be uncovered 
only to let the car pass. This is best done automatically in 
some such manner as is shown in Pig^. 12. The car is provided 

>ii rail A*. The arch-shaped upper part of this rail 
iijitns the trap doors when the car ascends, and 
lire (if tlie under part lets them down gently when 

§ 40 ELEVATORS. 25 

the car descends. To open the trap doors when the car 
descends, the rail R strikes with its lower portion bell- 
cranks C, C that are suitably connected to the door by 
rods D^ D, 



28, Signals must be considered in many cases as a neces- 
sary element of safety, especially in freight elevators with 
insufficient enclosures or trap-door elevators. Electric bells, 
one on each floor, so arranged that they commence and con- 
tinue to ring while the elevator passes the floor, are excellent 
safeguards; they not only warn persons against the approach- 
ing car, but tend towards the prevention of any attempt being 
made to operate the elevator from two floors at the same 

39. For passenger service, a signal is necessary to com- 
municate with the operator in the car from each floor. This 
is done very simply by means of a so-called aiiuunclator 
placed in the car and a push button on each floor near the 
elevator door. Where the traffic is but slight, this means of 
communication is satisfactory enough ; but where the service 
is rapid, it proves insufficient. Generally in such cases there 
are, at least, two elevators running all the time, one going 
up, the other down, and the would-be passenger should know 
which one to signal. For this purpose, so-called liidlctitoi's 
have been devised, which show on each floor simultaneously 
the whereabouts of the car and whether it is go'ng up or 


30, A simple mechanical device of this kind is shown in 
Fig. 13^ On the shaft A of the overhead sheave is mounted 
a worm D meshing with a worm-wheel li that is mounted 
on a shaft F. This shaft carries a chain wheel /, from 

//. S. W.—^6 




which motion is transferred by a chain ^Vand rods /"down 
the elevator shaft to each floor. The rods T are guided in 
plates W, one on each floor, and carry arms Z, Z. From 
these arms cords are carried over idlers X, X mounted on the 

pl;ites ICiind around small sheaves _/" in dial plates /attached 
at (.-nnspicuous places near the elevator doors. It will be 
understood th;it as the ear travels up nr down, the dial hand 
will move over the ligures displayed un the dial and thus 

§ 40 ELEVATORS. 27 

indicate the position of the car. The apparatus is made 
self-adjusting to rectify any disarrangement due to slipping 
of the chain. 

The wheel / only makes a part of a revolution. It is 
provided with lugs Pand Q that strike a stop 5 fixed to the 
frame of the machine as the car reaches its uppermost or 
lowermost positions, respectively. In case the apparatus has 
become deranged and indicates wrong, the one or the other 
of the lugs P, Q will strike the stop 5 before the car reaches 
its extreme point of travel and will bring the chain wheel / 
to a stop. On the return trip, the apparatus will then be 
readjusted. The chain wheel proper is mounted loosely on 
its shaft Fand is clamped thereto by friction disks y, / fast 
to the shaft and leather washers Z, L. 


31. The enormous traffic that has to be handled in the 
large office buildings has called for still more elaborate 
means of signalling than those afforded by annunciators and 
indicator dials. In such buildings the service is practically 
continuous and very swift ; the operator has no time to con- 
sult an annunciator to find out on which floor passengers 
are waiting. On the other hand, a passenger standing in 
front of a row of swift-running elevators and wishing to get 
the next car would have, if he were to consult indicator 
dials, to patrol up and down in front of the elevator doors, 
and would be likely to miss several cars running in the direc- 
tion in which he wants to go. 

32. The usual plan followed in such cases is to provide 
a signal which, when operated by the passenger, will be 
noticed by the operator on every car of the series early 
enough for him to stop at the particular floor where the sig- 
nal was given. The first car conductor answering the signal 
then destroys all the signals in the other cars. This plan 
has been successfully carried out in the Armstrong system, 
handled by the Elevator Supply and Repair Company, of 



New York. This system operates as follows: There a 
several push-button plates of two buttons, the one marked 
ufi and the other t/on-H, conveniently located on each floor. 
Over each elevator door is a double-light electric lantern, 
one light marked ii/i and the other doivn, A passenger 
desiring to signal the first car of a bank of elevators, pushes 
either the "' up " or "down " button. This sets the signal, 
and when the first car moving in the direction the passenger 
wishes to go reaches a point about three floors distant from" I 
that on which he is standing, the lamp in the "i 
" down" compartment of the signal lantern on the outside J 
of the elevator enclosure is automatically illuminated. ] 
When the first car approaching the waiting passenger going I 
in the direction he wishes, either up or down, reaches 
point about one floor distant, the "operator's signal" 
flashed, giving him ample time to stop his car before run- J 
ning past the floor. The operator's signal is a small lamp ] 
inside the car constantly in sight. The lamps in both the I 
lantern and car fixture remain illuminated until the car has I 
left the floor from which the signal was given. 

There can be no confusion of signals, because the operator 
can never have but one signal at a lime. Moreover, the 
system is entirely automatic. It allows the operator the j 
free use of his hands and he can thus give all his attention.J 
to the control of the car and the safety of his passengers. 1 
When no signal light appears in the car, the operator can I 
run at full speed, knowing that no passengers are waiting, f 
Should the first car that receives the signal be fully loaded J 
and therefore unable to stop for more passengers, the opera^fl 
tor may transfer the signal to the next car by pushing al 

AU this is accomplished by means of so-called commuia-4 
tors, one for each elevator, placed at the top of the shaft 1 
and run by a belt or chain from a pulley on the overhead J 
sheave shaft, in connection with a number of electromagnets. 1 
corresponding to the number of fiours in the building. Wei 
foregoa detailed description of the apparatus and the elec->j 
""ical connections thereof, since once installed, the apparatus ] 

30 ELEVATORS. ,^ § 40 

needs never to be disturbed. The engineer in charge 
should see to it that the contacts are kept clean and that 
the mercury cups used to make the various circuits have 
the proper amount of mercury. The current for the push- 
button circuits is furnished by a small motor-dynamo trans- 
forming an ordinary 110- volt lighting circuit to one of about 
10 volts. This motor-dynamo, of course, needs an occasional 
inspection, just the same as the other machinery. The 
current for the lanterns is taken from the lighting circuit 
direct. 1 


33. The name escalators has of late appeared in the 
terminology of elevator practice for what are commonly 
known as moviiiiar stairwaj-s. These moving stairways 
are, properly, not to be classed among elevators, being con- 
structed upon entirely different principles and are mentioned 
here only for sake of completeness and for the reason that 
they are destined to take the place of elevators in many 
instances. Thus it has been found that for short lifts, say 
one or two stories high, and where great numbers of people 
are to be transported, that adequate elevator capacity can 
be had only at great expense and sacrifice of floor space out 
of keeping with the profits accruing therefrom. 

The moving stairway consistsof an endless chain, to which 
are attached steps in such a manner that they form steps 
like those of an ordinary stairway. By an arrangement of 
cams, guide rails, and rollers these steps form a plane sur- 
face at the bottom and top landing. The accompanying 
sketch. Fig. 14, will convey the idea. It represents one of 
the latest designs of this class of passenger-transportation 
machinery built by the Otis Elevator Company, New York. 




1. Although steam fitting is a distinct trade by itself, 
engineers are sometimes called upon to do such work, and 
are often required to attend to, and to be responsible for, 
steam-heating plants. 

The following brief explanation of technical terms used in 
connection with systems of piping for steam distribution to 
radiators and heating coils will help to make the text matter 

2. A steam main is the pipe that conveys steam from 
the boiler or other source of supply and distributes it to 
the several branches. It is usually run along the cellar 
ceiling, being hung from the first-floor beams by adjustable 
iron hangers. It pitches down from its highest {x^nt near 
the boiler to its lowest point at the farther end of the main. 
The pitch should be at least A inch in 10 feet, so that the 
water of condensation may freely flow to the lower end of 
the main. 

An overlieacl main is a steam main that is run horizon- 
tally, or nearly so, at an elevation higher than the radiators 
that it supplies. This is supplied from the, boiler by a verti- 
cal risingr main. 

3. Risers are the vertical pipes that rise from floor to 
floor to convey steam from the sleam main to the radiators 

For notice <>f copyrix;ht, sco paj^e imtncMliutcly foll«>winj; the title page. 


or coils on the several floors. Drop risers are those in 
which the steam flows downwards to the radiators or coils 
from a steam main above, usually in the attic. 

4, Riser connections are the pipes, usually short and 
nearly horizontal, that connect the steam main to the lower 
ends of the risers or an overhead main to the upper ends of 
drop risers. 

6, Radiator connections are the pipes that connect the 
radiators to the risers or mains; they are usually short and 
seldom larger than 2-inch pipe. 

6. A return main is a nearly horizontal line of pipe, 
usually run near or under the cellar floor; it receives all 
water of condensation from the heating system and returns 
it to the boiler or otherwise disposes of it. 

7. Return risers are those vertical pipes that take the 
water of condensation from the radiators or coils on the sev- 
eral floors of a building and convey it to the return main. 

8. A drip pipe, relief, or bleeder is a small pipe used 
to drain water of condensation away from a low point, 
** pocket," or ** trap " in the steam pipes. 

J). A dry return main is one that is run above the 
water-line of the boiler and, consequently, is partly filled 
with steam. 

10. A Avet return main is one that is run below the 
water-line and is filled with water at all times. As a rule, 
this is more reliable than a dry return main except in places 
where the main is subject to frost. 

1 1. Coils area nunil)er of pipes stacked together for the 

purj)ose of j^iving off heat to the air around them. 

1'^. DlriH't nuliation is a term ap})lied to all kinds of 
Coils and radiators that are placed inside the rooms to be 
heated. This is the most conimoii practice in heating 


ordinary buildings because of its cheapness, effectiveness, 
and simplicity. 

13. Indirect radiation is a term applied to ail kinds of 
coils, radiators, and other forms of heating surfaces that 
are located outside the rooms to be warmed. Indirect radi- 
ators are usually hung from the cellar ceiling, are encased 
with a galvanized sheet-iron jacket, and are so constructed 
that fresh air from the outer atmosphere flows between the 
heating surfaces and enters the room, thus providing venti- 
lation as well as heat. The radiator itself, however, is con- 
cealed from view. 

14. Direct-indirect radiation, sometimes called semi- 
direct, is a term applied to all kinds of radiators and coils 
that are located in the rooms to be warmed and are pro- 
vided with means for fresh air to enter through them to the 
rooms from the outer atmosphere. 



16. The various systems of heating by steam may be 
classed in a general way as (1) high-pressure systems; 
(2) low-pressure systems ; (3) vacuum^ ox exhaust^ systems. 

In the first class are all systems of heating that work on a 
pressure greater than 10 pounds by the gauge; in the sec- 
ond class are those that work between atmospheric pressure 
and 10 pounds by the gauge ; in the third class are all sys- 
tems that work at a pressure lower than that of the atmos- 

Any one of these systems may be subdivided as follows: 
(1) The one-pipe system; (2) the tzvo-pipe syste7n ; (3) the 
tivo-pipe system luith separate return risers ; (4) the oifer head- 
main or drop-supply system. 

These, in turn, may be gravity-return systems or forced- 
return systems^ and they may have wet return or dry return 


mains. In the prravlty-i-etnrn system, the water of con- 
densation flows back to the boiler by gravity. This is used 
in cases where the full boiler pressure is allowed on the heat- 
ing system. It cannot be used elsewhere. 

The forced-return system is that in which the water of 
condensation is forced back to the boiler from the return 
mains of the heating system by a pump, steam loop, steam- 
return trap, or other such contrivance. This is used when 
the boiler pressure is higher than the pressure in the heat- 
ing system, as, for example, when a pressure-reducing valve 
is used on the steam-supply pipe to the heating system. 



16. The principal systems of piping that are now in 
vogue for heating purposes are shown in Figs. 1 to 4. These 
diagrams are intended to illustrate only the general arrange- 
ment of the piping, and many details are, therefore, omitted. 
The radiators a, /^ c are supposed to be located on different 
floors of a building and at various distances from the vertical 
supply pipes, or risers. It will be seen by careful inspection 
of the diagrams that the main difference between the several 
systems consists in the method of returning the water of 
condensation to the boiler. 


17, The one-p!pe system is shown in its simplest form 
in Fig. 1. Steam flows from the boiler />' through the risers 
and is convevcd to the radiators thromrh suitable branches. 
whic^h are nearly horizontal. All tin* water of condensation 
flows backwards throiit^h the sanu* pij)('s, moving in a contrary 
direction to the steam. All the nearly horizontal pipes. 



such as // and ^, must, therefore, be inclined sufficiently to 
secure the ready movement of the returning water. This is 
purely a one-pipe system and can only be used on very small 


18. The two-pipe system is illustrated by Fig. 2. Each 
radiator has two connections, one of which serves as an inlet 
for steam and the other as an outlet for water. The steam 
supply passes through the pipes h and s and the water flows 
back to the boiler through the return pipes r and /. The 
branch e that supplies steam to the radiator b, at a con- 
siderable distance from the riser, is inclined so that the water 

t - Ji 


1 r 

FlO. 1. 

Fig. 2. 

formed within it will flow towards the radiator. It is con- 
nected at k to the return pipe ^ by a small relief pipe, so 
that the water will be drained off and prevented from enter- 
ing the radiator. The steam main // is also inclined, if it is 
of any considerable length, so that the water formed within 
it will run towards the foot of the riser s. All the water 



formed in the pipes // and J is drained off by the relief 
pipe r' Thus the steam and the water are carefully 
separated at all points in the system. 


19. The separate-return system is shown in Fig. 3. 
The steam-supply pipes are the same in every respect as 

I'K;. 8. 

FlO. 4. 

in V\\r, •>. The returns, however, are different, each radiator 
])einj^^ provided with its own separate return pipe, as shown 

at r, ;■', /' ". 


*i(). 1'lu' drop syst 1^111 is shown in Fig. 4. The steam 

supply passes up the riser s to the top of the system, thence 
alotii; tlu' liorizontal pipe //, and descends through the drop 
pij)e //. The radiators are connected to the steam supply 
with siiii^lr pipes, precisely as in Fijr. 1. It will be seen that 
the water in ilie pipes // and </ moves in the same direction 
;islhc steam, instead of in the opposite direction, as in the 


single-pipe system. It is not necessary that the return 
should be made parallel with the steam-supply pipes, as they 
are shown in Figs. 2 and 3, but they may follow any conve- 
nient route back to the boiler. It is always advisable to make 
the returns as direct as practicable, care being taken, how- 
ever, to avoid straggling the pipes about the building in an 
unsightly fashion. 


21. The ** circulation,*' that is, the supply of steam, is far 
more certain in the two-pipe system than in the one- pipe 
system, because there is nothing to oppose or interfere with 
it at any time. Thus, a radiator at the end of a long horizon- 
tal branch, as at b in Fig. 1, is liable to have its supply 
interrupted by the formation of the returning water into 
** slugs,*' filling the bore of the pipe and causing water 
hammer; but when the pipes are arranged as in Fig. 2, 
the same formation may happen without causing any trouble 

When steam and water flow in the same pipe, the steam is 
likely to be wet, because the separation is less complete than 
when they are kept apart. When the currents flow in con- 
trary directions, the wetness of the steam is aggravated, and 
there is such an amount of mechanical interference between 
them that larger pipes are required than would otherwise be 
necessary, and there is also much greater liability to water 
hammer and sizzling noises. 


28. Occasionally a radiator will gradually fill up with 
water. This occurs in a one-pipe system when the steam 
valve remains nearly closed for a considerable time, but not 
shut tight. The steam is then condensed as rapidly as it 
enters, and the opening is so restricted that little water will 
escape. The same thing will happen in a two-pipe system 
if either of the valves is closed and the other remains open. 


By openinjx lx»th valves wide the water will almost noise- 
lessly pass out into the return, but in the one-pipe system, 
as Sf:H>n as the valve is opened, a violent struggle will begin 
l>etween the entering steam and the escaping water. The 
result will be a succession of rumbling, hammering, and 
snapping noises, which will continue for several minutes. 
If the supply piix? is long, as at c in Fig. 1, the noise is likely 
to be prolonged to an annoying extent. 

*iCi. In a large heating system, the amount of water to be 
returned to the b«^iler is so great that it becomes very diffi- 
cult to pass it through the steam-supply pipes without inter- 
fering seriously with the flow of steam to the radiators. 
The difficulty reaches a maximum in the coldest weather, 
the greatest amount of condensation occurring at the same 
time that the largest supply of steam is required. A single- 
pipe system must be carefully planned to avoid failure at 
this critical time, and it is gi>od policy to attach returns at 
some i>f the principal points to intercept the water and pre- 
vent its flood invr the riser connections. 

The two-pipe system, however, when carried out com- 
pletely, has a certainty of operation and freedom from noise, 
which in many cases makes it much superior to the onc- 
pipc system. 

srnnivi^ioN of large iie.vting systems. 

ti I. h is advisai>lc- to divide all heating systems that are 
<^f any c«»nsidrrai>lt' extent into several independent sec- 
tii»ns. L»>no «.r ir«ui])lesome horizontal branches may be 
reducctl t«> a niininuini by using indei>endent or special 
risers and varcliilly local ini:: them where they will supply 
the largest nunilxT of radiators to the best advantage. 
One riser may W used to supply almost any number of 
radiators, provided that none <^f them are located so far 
away as to make it tlifficult to drain the supply branch. 
Thus the {iucsii«'n of the number of risers to be used will be 
determined mainly by considering the drainage in the hori- 
xontal pipes. 


In a very tall building, a single riser may be sufficient, 
provided that the floors are of moderate dimensions; but if 
the building covers a large area of ground, two or more 
risers will be required. In all cases, however, it is advisable 
to have the branches as short as possible. 

Each section of a heating system should be made inde- 
pendent of the others, so that it can be closed down for 
repairs without affecting any other part of the system. 
Large straightway or gate valves should be placed close to 
the mains in both the supply and return riser connections. 



26. In planning any system of steam pipes, there are 
two things to be kept always in mind and that must be 
fully provided for; these are cirainagre and the movement 
of the pipes by expansion. No heating can be done with- 
out condensation, and the water thus produced must be dis- 
posed of promptly and completely and in a manner that will 
prevent interference with the steam supply. 

Expansion and contraction are inevitable, and the move- 
ment is rej>eated every time the system undergoes any 
considerable change in temperature. This movement must 
be provided for, otherwise it will break the joints and make 
serious trouble. 


26, The general arrangement of a steam main to sup- 
ply several risers is shown in Fig. o. The boiler a is set on 
the cellar or basement floor and furnishes steam to the 
entire system. The steam main h^ whose duty it is to convey 
steam to the several risers r, r, through which it flows to 
the radiators f/, d^ etc. placed within the rooms to be warmed, 
is connected to the steam space of the boiler and is so sus- 
pended from the floor joists by hangers that it will have a 



uniform fall from its bigbest poiat. which is immedia 
above the boiler, lo its lowest point f. A pitch of at 
\ inch in 14 feet is osually considered a sufficient fall for the 
main. When steam i^ generated in the boiler, il is forced 
into the steam main, from there into the risers, and thence 
into the radiators. The air that the pipes contain is forced 
out of the system to the atmosphere through air vents or 
small valves placed at suitable points in the system, usually J 

Upon each radiator at the end opposite the steam inlet. As 

stcitni riows through the main and the risers, part of it will 

be ctirulcnsed by heat being transmitted thTX>ugh the pipes 

o the air and objects sumnunding ihem. This condensed 

Asm will fall by gra\*ity to the bottom of the steam main, 

w lo ils lower end/, and enter tbe bottom of the boiler 

ough the rcttim pipe g. Tbe water of condeosKtioi 





from the radiators first accumulates in the base of the radi- 
ators until a sufficient hydrostatic head is formed to cause 
it to flow out of the radiators against the inflow of the 
steam. It then falls down the risers, through the riser con- 
nections, and into the steam main, also against the flow of 
the steam. If the riser connections to the steam main or 
radiator connections to the riser have too little pitch, or if 
the pipes are too small, the flow of the water of condensa- 
tion through them will be resisted by the flow of steam to 
such an extent that the water will not flow off as quickly as 
it is formed, the result of which will simply be that the 
water will accumulate in the pipe until it entirely closes it, 
when water hammer will take place. The steam main 
should be made sufficiently large to prevent such a differ- 
ence between the pressure in the boiler and that at the 
point/ as would cause the water to back up in the main 
and retard the flow of steam to any riser connection. 


87. Connection of Boiler Main. — In many cases it is 
advisable to connect the steam pipe leading from the boiler 
to the mains at a point near the middle of their length, as 
at a in Fig 6. The pipes may then be graded downwards 
from a in both directions. 

Fig. 6. 

28. Relays. — When a main or any horizontal steam- 
supply pipe has to be run a long distance, it becomes imprac- 
ticable to grade it uniformly throughout its whole length. 

H. 5". V,—27 

because the far end dmps too low to be drained conveniently, 
111 such a case, the difficulty may be overcome by introducing 
Virtual offsets, or i-elnys, in the line of pipe, as shown in 

Fig. 7, A relief pipe may then tie attached at the foot of 
each offset, as at a. The steam should always flow down 
grade— that is, in the direction of the arrow. 

29. ttlsep Connections. — The riser connections in one- 
pipe systems may be made as shown in Fig. 8 or 9. They 
permit the mains to be 
kept from the founda- 
tion walls sufficiently 
to allow them to be 
gotten at conveniently 
for screwing together 
and also for putting on 
coverings, etc. 

The piece a serves as 
a spring pleoe, and 
permits both the main 
and the riser to shift 
slightly by expansion- 
In Fig. 8 the spring 
^™- * piece is bent, to insure 

good drainage. The construction shown in Fig. 10 is some- 
times used forthe same purpose, the grade being secured by 
cutting the thread crooked at the end o. This is bad prac- 
tice, because the teeth of the dies cut too deeply into the 
pipe on one side and weaken it seriously. 




Pig. 9. 

30. A riser should not be connected directly into the 
top of the main by a T, unless both pipes are very short. If 
the riser is long, its weight will cause the main to sag, and 
if the connections to the radiators above are rigid, the down- 
ward expansion will 
either bend the pipe 
or lift the radiators. 

The connections" to 
radiator branches, etc. 
should, if possible, be 
made with Y fittings. 
Plain T connections 
are objectionable in a 
one-pipe system, be- 
cause the water of con- 
densation runs down 
upon the interior sur- 
face of the riser and is very apt to flow outwards into the 
branch, thus increasing the difficulty of draining it properly. 

31. In the case of risers that are very high, provision 

must be made for ex- 
pansion. This may 
be done by making 
slightly inclined offsets 
in the pipe, at inter- 
vals not greater than 
two stories apart. If 
the weight is consider- 
able, the riser must 
be supported by other 
means than its con- 
nections to horizontal 
Fio. 10. branches. 

38. Radiator Connections. — The ordinary mode of 
connecting a direct radiator to the riser in a one-pipe sys- 
tem is shown in Fig. II. The pipe a serves as a spring 
piece to allow the riser to expand without lifting the radiator 


and the drop i insures that the water shall drain away 

33. When the radiator 
is at a long distance from 
the riser, so that the drain- 
age becomes difficult, it is 
advisable to put in a double 
connection, as shown in 
Fig. la. The supply pipe a 
and the drain pipe tt are 
both connected to the riser 
r, and a siphon is placed at 
d. All the water that flows 
through a will thus pass 
into the drain pipe without 
entering the radiator. 

Fii;. II. 34. The connection 

n in Fiyj, lit permits the radiator to beset very close 
h: riser, and at the same time the spring piece a is 
mg and llc.\ible that the riser may move considerably 

without nKiking ;iny trouble. It also has the advantage 
of being entirely almve the floor, .so that it is accessible 
»t all times, and iho \"ilve is brought out into a convenient 

3S. When the viTtio.-il movement of the riser is excess- 
«i the Bwivel connection shown in Fig. 1-1 may be used. 



In this form of connection, the pipe a may be inclined any 
amount desired, in order to 
secure perfect drainage. 

36. Returns.— The down- 
ward grade given to return 
pipes should be as nearly uni- 
form as practicable. There 
should be no upward bends or 
loops, because air is likely to 
collect in them and impede 
the flow of the water. Care 
must be taken, also, to avoid 
forming sags or depressions in 
which water will accumulate. 

When the returns are connected to a main that is located 
above the water level, and if there is any perceptible differ- 
ence in the pressures at the various radiators thus con- 
nected, the steam will flow 
backwards through the 
return pipes towards the 
points of lowest pressure, 
and in most cases will 
spoil the drainage and 
cause water hammer. As 
I the fall of pressure at any 
radiator is due solely to 
the resistance that the 
supply pipes offer the flow 
of steam, it follows that 
the trouble in that case 
may be remedied by in- 
creasing the diameter of 
the supply pipes. It is quite impracticable, however, to 
connect drain pipes or returns leading from radiators 
having a considerable difference in pressure with a dry 
return main. 

37. When the return main is located below the water 
level, the water that it contains acts as a barrier to prevent 




the passage of steam from one return to another. Thus the 
steam is compelled to pass through the system in the 
direction it was intended to go, instead of making a short 
circuit or by-pasH, This makes a positive circulating job. 

38, Water l^evel In Itetums. — There is always more 
or less difference in the pressure of the steam in the boiler 
and at the end of a line where the return is connected; 

;refore, the water will rise in the return to a height above 
the water level in the boiler sufficient to balance the differ- 
ce in pressure. As this difference varies in the several 
urns, the water is likely to stand at different heights in 
each. The hot water rises about 2fl inches for each pound 
of difference in pressure. If there is a water pocket any- 
where in the return pipe, the water will back from it towards 
the radiator until it balances the difference in pressure upon 
le opposite sides of the water. Thus a radiator that is 
■ell above the pro[>er water-line may be flooded with back 
water if there is a water pocket near it in the return. 

39. Size of Pipe Requlretl. — The proper size of pipe is 
one that will furnish a sufficient amount of steam without 
undue fall of pressure, and at the same time will not 
present an unnecessary amount of surface for condensation. 

It is found in practice, when steam having a pressure less 
than 5 pounds is used, that the proper sines for branches to 
radiators are about as follows: 



Heating Surface of Radiators. 

24 square feet or less 

Above 24 and not exceeding 00 square feet 

Above 60 and not exceeding 100 square feet. . . . 
Above 100 square feet 






Heating Surface of Radiators. 

48 square feet or less 

Above 48 and not exceeding 90 square feet 
Above 90 square feet 















40# These data are for direct radiators, and if indirect 
radiators, which condense more steam per square foot, are 
used, the size of the pipes should be increased. The proper 
sizes are given in the following table : 




Heating Surface of Indirect Radiators. 











30 SQuare feet or less 



Above 30 and not exceeding 50 square feet 
Above 50 and not exceeding 100 square feet 
Above 100 and not exceeding 1 00 square feet 

41, The size of steam mains or of principal risers 

may be computed by the following rule: 


Rule 1. — Divide the amount of direct Juating surface in 
square feet by 10(f ; divide the quotient by . 7So4 : then 
extract the square root of the quotient ; the result will be the 
diameter of the pipe in inches. 

Kx AMPLE.— What diameter of main steam pipe is required to supply 
dir-(fct radiators having a total heating surface of 3.800 square feet ? 

Solution.— 4,/ -^.^ -s- .'J'8''>4 = 6.9 inches; or, in practice. 7-inch 
pil)e. Ans. 

42. To find the amount of radiator surface that may be 
|)r()[)erly supplied by any given size of pipe, the reverse 
process should be followed: 

Ilule 2. — Multiply the square of the diameter of the pipe 

in inches by . 785^ ; then multiply the result by 100 ; the result 
IS the total amount of heating surface in square feet which 
the pipe will supply. 

Example.— What amount of direct heating surface may be supplied 
by a steam pipe 7 inches in diameter ? 

Solution.— 7^ x 7854 x 100 = 8,848 sq. ft. nearly. Ans. 

\X\. Kxpansion Pieces. — The iron pipes that are used 
in steam fittinji: expand about IJ inches per hundred feet in 
l(!nji;th. In lonji^ lines of pipe this expansion must be pro- 
vided for, otherwise it will make trouble by breaking con- 
nections or shoving apparatus out of place. In large pipes 
the expansion may be taken up by means of an ordinary 
expiinsion slidinj^ joint. 

'i'liesc slidini^ joints are generally objectionable because 
of the ("are n^cjuired to keep the packing tight and in good 
<»r(ler. 'i'lu- sliding lul)e should be made of brass or bronze, 
to prevent its ( orroding and sticking fast. 

•11. Other modes of providing for the linear expansion 
of pipe, especially in the smaller sizes, are shown in Figs. 15 
to IS. In Fig. IT) an offset is made in the pipe, and the 
piece a, which is c ailed a spring ])leee, is made long enough 
to bend or spring sufficiently to permit the necessary 




movement of the pipes h, c without straining the threads 
excessively or cracking the fittings. 

FlO. 15. 

45. In Fig. 10 the spring piece a is bent into a loop, as 

Fig. 16. 

shown. Pipes of this kind are usually made of copper, with 
brass flanges brazed on. 

FIG. 17. 

46. In Fig. 17 the pipe a is bent into a coil. This form 
affords such an easy bend that ordinary wrought-iron pipe 

■steam heating, 

may be used without difficulty. The diameter of the circle 
should be large enough to spring the desired amount with- 
out serious straining. 

Care must be taken in using the devices shown in Figs. 16 
and 17 to avoid forming a pocket in which water or air may 
collect. A pocket may usually be prevented by extending 
the loop or coil horizontally instead of vertically. 

47. In Fig. 18 the connections are made so as to s^vlvel 
instead of bend. When the pipes b move endwise by expan- 



sion, the nipples c turn slightly in their threads and thus 
permit the piece a to swing to the requisite extent. 

48. During the erection of a steam-heating plant, the 
matter of expansion must be carefully considered. The 
best point for fastening each principal pipe so that its 
expansion will cause the least disturbance should be deter- 
mined by close examination. Care must be taken to have 
every such pipe free at its ends and to see that its connec- 
tions or branches are not bound or rendered immovable by 
plaster, brick, wood, or iron beams or columns. The pipe 
fitter should personally inspect every such point and make 
sure that the pipe system is free to expand before steam is 
turned on. 


'49. Special PIttlnfp*. — Fig. 11^ sh'iws a fitting designed 
to make a connection between a radiator branch and a c 
tinuous riser. The partition a is 
curved so as to secure a proper sup- 
ply lo the radiator, and the pas- 
sage d permits the main current to 
ascend without excessive obstruc- 
tion. It is intended to take the 
place of. the common Rttings shown , 
in Pig. 21 that are usually employed 
for the same purpose, and it also 
lias the advantage of preserving 
the alinement of the parts of the 
riser. Fig. 20 is a variety of T Y 
■which is designed for the same or 
similar use as Fig. 19. p„,_ m, 

50. Fig. 22 shows an eewntric MHliK-cr, which sitrvrs 
to bring the bottoms of the connected |tipi-s tu thu same 
level and thus prevents the Imlg- 
ment of water at that fxjini. This 
is particularly useful on steam mains 
and other nearly horizontal steam 

61. Fig. 23 is a croMs, or double T, 
having the branches at ;i higher loi 

than the main pipe. This form of connection insures the 
proper drainage of the branches into the main steam pipe 



SZ. Method of Proc«daiv. — Xrw buildings are jnped 
while the work of constmctioo proceeds, as »ood as the 
walls are ap and the roof is on. On large jolts the risers are 
usually put up Grst, next the horizontal branches are con- 
structed, proceeding alvaj-s from the riser towards the 
radiators, and lastly the mains are put in place. The 
retttms are constructed at the same time and in a similar 

In many cases, bowex'er, particularly in small buildings, 
the mains are run in first, then the risers, and finally the 
radiator connections. This latter method avoids the use of 
" right and left " fittings, or unions, -between the risers and 
the mains. 

All radiator connections should be promptly capped 
soon as erected, and all openings in T's and other fittii 
should be plug){ed at once, so that no dirt may get into tl 

£3. Tcwtlng. — The piping should be tested for tightnei 
before it is covered by plaster or flooring, so that if j 
defective titlings ur split pipes are discovered, they may t 
xd without trouble. The testing is done by fillir 
i system full of water, every opening being tightlyf 





closed, and then applying pressure by means of a force 
pump. The pressure is increased until the gauge shows 
from 100 to 150 pounds per square inch. Another test 
should be made with steam before the pipes are covered, 
if possible. This will determine whether the expansion is 
properly provided for and whether the system is in working 
order. The steam pressure used should not greatly exceed 
the proposed working pressure. 

54, Clearance. — All steam pipes should be kept out of 
contact with woodwork or other combustible materials. A 
clearance of at least 2 inches should be maintained at all 
points, and where this cannot be had, special protection 
should be provided. Return pipes are liable to be full of 
hot steam at times, therefore they must be guarded the 
same as steam-supply pipes. 

55, Floor and Coilinir Flanpres. — Fig. 24 shows the 
manner of using floor and ceiling flanges to protect the 



Fig. 24. 

woodwork where a steam [)ipe passes through an ordinary 
floor. When the ceiling flange v is secured to the pipe by a 




setscrew, as shown, allowance must be made in setting it 
for the vertical expansion of the pipe, otherwise it will be I 
liable to break the plaster forming the ceiling when thel 
steam is turned on; or the ceiling flanges may be secured! 
after the steam is on. A better construction is to connect I 
the upper and lower flanges by a nipple a size or two larger I 
than the riser, and have a current of air flowing through the 1 
spaces between the pipes and any combustible material. 



56. Saving Efffctcd.— The exhaust sj-stem is in every 1 
respect a low-pressure system, except that it is provided I 
with special apparatus that adapts it to receive the exhaust I 
steam from engines and pumps. It is used only for the ■ 
purpose of utilizing and saving the heat in exhaust steam | 
that would otherwise go lo waste. 

The magnitude of this waste may be easily seen when it is J 
considered that exhaust steam at 6 pounds gauge pressure! 
contains 971 British thermal units per pound that are! 
available for heating, and if not thus used, would be dis-l 
charged through the exhaust pipe into the atmosphere. 

The practice of allowing exhaust steam to escape into the! 
atmosphere in any situation where it can be used 
heating apparatus, either for housewarming or heating J 
liquids, etc., is, therefore, inexcusably wasteful. 

57. General ArrHiiBeinont.^ — The general arrange- I 
ment of apparatus for controlling the steam supply and J 
drainage in an exhaust system is shown in Fig. 35. The''! 
steam-heating main a is connected to the exhaust pipe ^andl 
also to a pipe c that supplies live steam from the boilers.! 
This steam passes through a pressure-reducing valve ^ and ■ 
is lowered in pressure to the desired amount before entering 
the healing main. By this arrangement the heating system 
will be supplied with exhaust steam as long as the engines 




are in operation, but if for any reason the supply becomes 
insufficient to maintain the proper pressure, then live steam 
will enter through the reducing valve and make up the 
deficiency. If the supply of exhaust steam becomes excess- 
ive, so that the pressure rises unduly, the excess will escape 
by opening the back-pressure valve / and blowing into the 

atmosphere. When the engines are stopped, the steam in 
the heating apparatus is prevented from passing backwards 
and filling them with water by means of the check-valve ^. 
This valve is similar to the valve / in construction and is 
so nearly balanced by its counter weight that it will open 
very easily. The relief vliIvc / is iisiuilly adjusted to 


blow off at a pressure about 1 pound higher than that main- 
tained by the reducing valve ('. 

The exhaust steam is passed through ii separator d before 
entering the healing system, for the purpose of removing 
the entrained water, and especially for removing the oil 
that accompanies it from the engine, 

i»8. Dlsposul of nraliio^te. — The drainage from Ihe 
heating apparatus is collected in the pipe // and is returned 
to the boiler by means of a pump p, as shown. The returns 
have no direct connection with the boiler, consequently the 
water level in them may be maintained at any convenient 
height, as at i i. This is accomplished by means of the 
pump and its governor in. The pmnp grovenior is merely 
a closed vessel containing a float u that rises and falls with 
the water level. The steam that drives the pump is taken 
from the high-pressure pipe c through the stop- valve « and 
passes through a throttle valve / that is controlled by the 
float. When the water rises above the desired level, the 
float opens the throttle and starts the pump; when it sub- 
■ sides, the float is lowered and shuts off the steam. The 
exhaust from the pump is turned into the exhaust main 
through the pipe s. The pump governor is connected to 
the heating main a by a small pipe c for the purpose of 
equalizing the pressure on top of the water therein. 

50. liocatloii of Valves. ^Valves are provided in the 
main pipes, at /' and !', for the purpose of shutting off the 
heating apparatus during the summer season. It will be 
noted that these valves are located so that they do not 
interfere with the supply of steam to the pump nor with 
the exhaust therefrom. The returns are shut from the 
pump by the valve r. and an independent water supply is 
attached at w. The pump delivers through the pipe / to 
the boiler. 

60. Care must be taken to locate the valves /and g in 
proper relation to each other, as shown. If the check-valve 
is placed between the heating main n and the valve /^and 
the reducing valve i should get out of order, the pressur>ej 


would rise in the heating system until it equalled that in the 
boiler. This would probably burst the radiators and do 
serious damage. The safety of the whole apparatus depends 
on the good working condition of the relief valve/. 


61, General Description. — The vacuum system of 

steam heating differs from all others in one important par- 
ticular, which is, that a vacuum, more or less perfect, is 
constantly maintained in the returns. This permits the 
system to be operated with steam of any convenient 
pressure, high or low, and from any source, either exhaust 
or otherwise. The pressure and temperature throughout 
the whole system may be adjusted and maintained at any 
degree between full-boiler pressure and a low vacuum, 
thus making the system adjustable to suit all conditions of 
weather and service. 

Generally the system is operated with exhaust steam, the 
supply being arranged as shown in Fig. 25. The piping is 
usually arranged on the two-pipe system, and the returns 
are generally made independent, although it is not necessary 
to do so in all cases. 

63. Essential Features. — Fig. 26 shows the essential 
features of the system. The returns (7, a are connected to 
a receiver ^, which collects all the air and water in the sys- 
tem. These are pumped out by means of the vacuum 
pump 7\ which thus maintains a constant vacuum of any 
degree desired in the returns. 

By this arrangement any steam may be used in the radia- 
tors that is warm enough to operate the traps or *' thermo- 
static valves" that are placed on the return end of each 
radiator to open automatically when water or air is required 
to pass through, but to close when steam begins to pass 
through. This prevents the returns from becoming filled 
with steam. The vacuum system permits steam to be used 
at a pressure far below that of the atmosphere and at any 
temperature down to about 140°, the limit being fixed only 

H. S. v.— 28 


by the ability of the pump to keep up the vacuum in the 

63. There are various forms of exhausting apparatus that 
may be used in place of the pump, to maintain the vacuum, 
such as "injector condensers," etc., but as they are not an 
essential part of this system, they will not be described here. 


The water and air that are drawn from the receiver by the 
vacuum pump are discharged into an open tank, from which 
ihe air readily escapes. The water is then pumped back 
into tht; boiicr by any ordinary feed-pump. 

04. In some cases, the fresh, cold water, which is other- 
wise required to feed the boilers, is injected into the receiver 
in a series of fine streams through the pipe u; the objoct 
being to condense asmucli as possiljleof the steam that may 
be i»resent and tiiiis ihe vacmnn. At the same 
time that the water becomes warmed it gives up the air 
accompanying it. thus increiisin^j the amount to be removed 
by the pumji. This air e\|>ands into the vacuum and partially 
neiUralizcs the effect of the condensation. Thus it will be 


seen that the introduction of the feedwater into the system at 
this point is of doubtful utility. If it is sent through an 
ordinary feedwater heater instead, it will become much 
hotter and the air will be eliminated without difficulty. 

65, Advantages. — It will be understood that when the 
exhaust steam from an engine is turned into the ordinary 
low-pressure heating system, the back pressure is increased, 
and the efficiency of the engine is correspondingly decreased, 
sometimes to such an extent as to become very detrimental. 

One of the principal advantages of the vacuum system is 
that a great part of the back pressure is taken off the engines, 
and the capacity of the engines to do useful work is thereby 

The size of the piping required for the vacuum system of 
steam heating is about the same as for the ordinary low-pres- 
sure system. The volume of the steam required is greater, 
owing to the low pressure, and the amount of heat per cubic 
foot is correspondingly less than that found in ordinary heat- 
ing systems, but the difference between the pressures of the 
steam in the supply pipes and in the returns is so great that 
the volume of steam necessary to carry the amount of heat 
required is driven through the pipes without difficulty. 

The radiators, however, must be larger than for any other 
system, in proportion as the temperature of the steam used 
is lower. 


66, The district system of steam heating is practiced 
in large towns and cities by means of steam mains that are 
laid underground through the streets. The arrangement of 
the connections from the street mains to the house pipes is 
shown in Fig. 27. The service pipe a is provided with a 
valve b inside the basement wall, so that the house system 
can be shut off when desired. The steam passes through a 
pressure-reducing valve c and thence into the distributing 
pipe or house main e. The water that may enter from the 
service pipe is led away by the drain pipe d. The returns 



are all connected into the pipe/, which is submerged below 
the water level. The level of the water in the returns is 
fixed by the elevation givBn the steam trap /; thus, in the 
figure, it is at the line g. The hot water from the trap 
should never be discharged directly into the house drains, 
because of its destructive effect upon the pipes, but should 
lie cooled l)efore escaping to the sewers, by first allowing it 
tu How through a coil of pipes. This coil is usually called a 

"cooling coil It shai 

drainage system 

deep, sealed trap This 

uld ntver deliver directly into the 
all cases should de]i\er into a 

s IS to prevent drain air entering the 
heating system or the building. The trap, orhotwell, should 
always deliver into Ihe house-sewer connection on the sewer 
side of the main-drain trap, to prevent hot vapors passing 
up the iron drainage system in the building. 




67. Air Tents. — All automatic air vents on steam-heating 
systems are thermostatic in principle; that is, they are con- 
trolled by a difference in temperature between the steam and 
the air that is to be ex- 
pelled from the heat- 
ing apparatus. 

Fig. 28 shows the 
construction of an or- 
dinary air vent. The 
shank a is screwed into 
a radiator tube and the 
nozzle d is connected 
to a suitable drip pipe. 
The valve c is a rod 
composed of some expans 
the steam urifice by i 

material that is adjusted against 

When air enters 
the orifice e instead of 
steam, the rod c cools and 
shortens slightly, thus 
opening the orifice and 
permitting the air to flow 
through. As soon as hot 
steam arrives, however, 
the rod expands and 
again closes the vent. 

68. The length of the 
expansible element that 
is exposed to the air or 
steam is very small, con- 
sequently the opening of 
the vent will be veryslight 
and quite slow in opera- 
tion. This is improved in 
the construction shown in 


Fig. 29. The expansible rod a is much longer and is hollow. 
Its whole interior surface is exposed to the steam or air at 
all times. The lower end is screwed fast to the body of the 
vent and the upper end draws away from the valve // when 
contraction occurs from the cooling influence of air. The 
valve 6 has a long stem that screws into the bottom of the 
chamber, and it is easily adjusted by means of a screw- 
driver when the cap c is removed. The air passes through 
the vent hole d. A small screw valve f is added for relief 
by hand when desired. 

Both of the devices shown will permit the escape of water 
as readily as air, therefore they should be provided with 
^^^^ suitable drip pipes. Other- 

■■pH wise, they are very liable to 

W V discharge water at almost 

JUL any time and thus make 

^^ 1 1 ^V serious trouble. 


69. In Fig. 30 the trouble 
mentioned in Art. 68 is 
remedied by attaching a 
cup or float a to the stem of 
the air valve ^. This stem 
rests loosely on the bent 
spring r, and when the 
chamber fills with water, the 
float will lift the valve and 
close the vent. The valve is 
opened to discharge air by 
the bending of the spring. 

F:o. an. 
which is made of two strips of different metals firmly sold- 
ered together. These contract by different amounts when 
cooled, thus bending the spring and allowing the valve to 

open slightly. 

10. The proper place to attach an air vent to a radiator 
or coil is at a point as far as practicable from the -steam 
inlet, so as to prevent the current that moves towards the 

vent carrying hot steam to it and thiit 
the air has escaped. 

Traps.— Return traps are used only for 
ater of cundensation to the boiler. It is 

71. Retur 

returning the 
immaterial whether 
the pressure in the 
boiler greatly exceeds 
that in the heating 
apparatusornot ; they 
are equally serviceable 
for all cases. They 
require to be set above 
the water level in the 
boiler, at a sufficient 
elevation to allow the 
water to flow from 
them into the boiler 
by gravity. 

72. Pig, 31 shows ^^^ ^i 

a very common form 

of a return trap. It is composed of a globe a that performs 
the duty of a condenser and receiver, and the connecting 
pipes on which are attached the valve /' and check-valves c 
and (/. The pipe on which c is placed joins the boiler, usually 
below the water-line, and the pipe on which </ is placed 
joins a receiver that is set at the lowest ends of the return 
mains to receive water of condensation from the heating 

The pipe on which (r is placed joins the steam space of 
the boiler. A rotary slide valve ^ engages with a rocking 
casting / by means of a connecting link ^, the engaging 
point between/ and ^ being provided with slack motion, as 

A lever A having a float t' on one end (inside the trap) 
and a counterpoise weight on the other end also engages 
with the casting/ by a slack -mot ion connection, as shown, 


A track is formed in llie casting _/" along which the solid ball 
shown may roll. 

73. The action of the trap is as follows: When a vacuum 
has been formed in the globe ti by the condensation of 
steam, water of condensation from the receiver will flow 
through (/ and into the trap, as shown, and will continue 
flowing until the trap is full or the receiver empty, provi- 
ding the trap is not set too high. As the water rises in the 
trap, the float / will rise with it and the loaded end of the 
lever A will descend correspondingly. As this movement 
of A continues, the stud that engages /i with the casting / 
pushes down that end of y, thereby bringing the track nearer 
a level position. This it does without moving the rotary 
valve f on the steam connection, because of the slack motion 
between i"- and/". 

As soon as the end of the track on which the ball rests is 
raised above the level of the other end, the ball will roll 
along the track, strike the opposite hooked end, and cause 
it to fall rapidly, opening the steam valve c to its full extent. 
At this point, the trap is about full of water, and since the 
full boiler pressure is now placed on the surface of the water 
in a and since this water is higher than that in the boiler, 
it will be easily seen that the water in a will simply fall by 
gravity into the boiler. 

As the water drains from a, the float / will descend, and 
when it has reached the bottom of the globe, the track will 
be tilted in the opposite direction by the ball, when the 
steam valve f will be suddenly closed and the trap will be 
prepared to receive another charge from the heating system 
as the steam condenses in the globe. 

74. The height to which water can be lifted is limited by 
the difference between the pressure in the receiver and the 
vacuum formed in the trap. As nearly all varieties of 
return traps depend on the formation of a vacuum in order 
to become filled with water, it is essential that air be care- 
fully excluded from them. 



76. Form of Heating: Surfaeen. — Heating surfaces, 
i. e., the exterior surfaces of radiators and coils, that have 
no projections of any kind are classified as plain surfaces, 
while those having ribs, knobs, pins, or other projecting 
parts are called extended surfaces. 

The object sought in the construction of extended surfaces 
is to make the area of the emitting surface greater than 
that of the absorbing surface. By this means heat may be 
transferred from a fluid that gives it off readily to one that 
takes it up slowly with but little decrease in temperature of 
the heat-transmitting surfaces. 

A plate having extended surfaces will emit more heat per 
hour than the same plate without the extensions, but less 
than a plain plate having the same actual area of exposed 

Extended surfaces have no advantage over plain surfaces 
unless the velocity of the air passing over them is sufficient 
to sweep them clean of hot air as rapidly as it is formed. 
When air is moved wholly by convection, as is the case when 
a radiator stands in still air, the plain surfaces clear them- 
selves of hot air better than do the extended surfaces and 
are, therefore, more effective. 

76. Efficiency of Radiators. — The efficiency of a heater 
or radiator will increase as the velocity of air passing over 
it is increased, but not in the same proportion. With 
increased velocity, the duration of contact of air with the 
hot surface is shortened and the rise of temperature will be 
less, but the quantity of air heated will be increased so much 
that the total heat given off from the radiator per square 
foot of surface per hour will be increased. 

77. Arrangement of Heating Surfaces. — The effi- 
ciency of a radiator will depend, to a considerable extent, 
on the direction in which the air is moved over the heat- 
ing surfaces. Ficf. 32 shows a vertical tube standing in 
still air. The tube is heated bv steam and its surface has a 




temperature that is practically uniform throughout. The 

air, which is warmed at the lower 








end of the tube, flows upwards and 
envelops the upper part in a cur- 
rent of hot air. The emission of 
heat will be slower from the upper 
part of the tube than from the 
lower part, because the difference 
in temperature between the air 
and metal is less. 

The temperature at the various 
points is marked on the sketch. 

A similar loss of efficiency oc- 
curs in a common coil of horizon- 
tal pipes laid vertically over one 
another, as shown in Fig. 33. The 
upper pipes are enveloped in the 
warm air that has been heated 
by the lower pipes. 

78, The maximum efficiency 
can be attained by placing the 
coil or radiator in a horizontal 
position, as indicated in Fig. 34. 
Each tube will then operate upon air of equally low tem- 
perature, and, consequently, the rate of emission will be 


Fig. ;i4. 

greater than in the cases shown in Figs. 32 and 33. 

71)« If radiator tubes are grouped together in large num- 
bers, as in Fii^. 155, the efficiency of the tubes in the interior 
of the group will be much less than that of the outside 
tubes, because the access of cold air to them is practically 
cut off, and they can act only on air that has already been 
warmed bv the outer tubes. 



Fig. aa. 

Fig. 33. 




Their efficiency is still further reduced by the fact that 
nearly all the heat that they emit by radiation is intercepted 
and cut off by the outer tubes. 

o o o o o o 

o o o o o o 

o o o o o o 

o o o o o o 

o o o o o o 

Fig. 35. 

Therefore, the most effective form of radiator or coil for 
direct heating is one "having only a single row of tubes. 

80« Flue llmllators. — Figs. 36 and 37 show varieties of 
radiator tubes that are so shaped that, when they are 
assembled in a group, 

they enclose vertical air .K^;':^e^^^^^^^^^^^v^^^^^'g^^^??^^ 
flues as shown at a. The 
bases of the tubes are 
set high enough above 
the floor to permit an 
abundant flow of air 
into the flues at the 

bottom. Radiators con- ^^^' ^' 

structed in this manner are called flue nullators. 


The advantages uf this coDslriiction are that the interior" 
parts of the radiator are fairly well supplied with air and 
that the flues impart a 
higher velocity to the air 
than it would otherwise 
obtain. The emissive ca-l 
pai-ity of the two form*' 
shown in Figs. 36 and 3? 
will differ greatly with" 
the relative amount o£ 
plain and extended heat-' 
ing surfaces that they 
(in of heating surface to 

alTurd, and also with the propor 
the area of the flues. 

81. Continuous Flat Coll. — The continuous flat coil. 
Fig. 38, is made of straight pipe connected by return bends. 

The circulation of the fluid thrniigh ii is direct and certain, 
and it is regarded as the must efficient form of radiator in 
common use. 

82. Miter Coll.— A miter roil is shown in Fig. .3W. the 
pipes being connected between two manifolds (i and b. The 
steam moves forwards simultaneously through all the pipes; 
therefore, its velocity will be one-sixth the rale in a single 



pipe, as in Fiy. •'!i*. The circulation is likely to he uneven, 
because the fluid entering at a' will naturally, owing to its 
momentum, flow to the end of the manifold, and so a greater 
quantity willenter the pipe ^ than pipe/". The path through 
e c is shorter than through ye/, and, the friction being less, 
the main part of the current will go that way. 

It will be noted that all the horizontal pipes are connected 
to the manifold a by means of elbows and vertical pipes. 
This must always be done, so as to permit the several pipes 
to expand independently, as their varying temperatures may 
require. The vertical pipes will bend or yield sufficiently to 
accommodate the difference in expansion. 

S3. Hnnlfnld Cotl.— If a coil is made by connecting twr 
tnanifolds, as in Fig. 40, it will he difficult to keep it steam 
tight. The upper pipes will expand more than the lowei 


ones, and they will either bulge anil spring, as shown, or 
they will crack or break some of the connections, 

84. Box Coll. — When several flat coils are grouped 
together, as shown in Fig. 41, the construction is called a 
box coll. 

The spring pieces of a coil should be put together with 
right-and-left screw joints, so that the coll may be readily 
disconnected at any time and without unnecessary labor. 


85. Size of Pipe for Colls.— The size of pipe used fi 
constructing coils depends chiefly on the pressure of steam 
to be used, the length of the coil, and the force of the circu- 
lation through it. A coil like Fig. 39 could be made of 
smaller pipe than one like Fig. 38. because the current of 
heating fluid is diffused throughout the whole series instead 
of passing entirely through each pipe. The difference, how- 
ever, would seldom exceed one or two sizes of pipe. The 
customary size of pipe used is from I inch to IJ inches — the 
latter being used for exhaust-steam heating. 

Pipe coils must be arranged so that all water that is con- 
densed within them may flow easily towards their outlets. 

86. Tfason Tube. — Fig. 43 shows a lube called the 
Nft9«»n tube. It is connected to the radiator base by a 
single screw joint and is divided into two passages by 
means of a sheet-iron plate n that extends nearly to tbl 








top of the tube, as shown. 
The steam rises on one side, 
passes over the end of the 
plate, and descends on the 
opposite side of the lube. 
Each tube thus forms a com- 
plete /oa/i, or circuit. 

H7. KuiKly I.ooi,; — 
Fig. 43 shows the Bundy 
loop, in longitudinal section 
at A and cross-section at li. 
This, also, is screwed into 
a cast-iron radiator base of 

Plo. ■ 

suitable shape, 
the steam move 
one branch of 
tube and down 





88, Detroit Loop. 

The Detroit loop is 
shown in Fig. 44. Each 
loop is complete in it- 
|. self and requires no 
base or supply chamber. The loops are connected together, 
in any number desired, by means of nipples tt and c. When 
the connection at the top is not desired, the loops are bound 



itigclhcr by a bolt that passes through the space between , 
ihcm, shown in the end view. 

The ciinstruction of this class of loops is often varied so j 
that they comprise three or even four parallel tubes. They ' 
are also modified so as to form flue radiators. 

8!). I'ln Rtullalor.^ — ^Fig, 4.5 shows an extended-surface 
indirect radiator that is in extensive use for indirect heating. 

It is called a pin iwllator because the extensions of the^ 
healing surface are made in [he shape of small conical pins. 
The air flows up between the sections and impinges against I 
the pins. 

90. FofctHl-dnvrt hoatci-s, which are commonly used j 
for heating air on a large scale, where forced draft is used, 
are constructed in a manner similar to that shown in Fig. 4fl; | 
(^) is an elevation and (ii) a plan. The tubes are of 1-inch I 
steel or wrought-iron pipe and are connected at the top by 1 



Ppipes instead of return bends, thus preventing all dis- 
tortion by unequal expansion. 

The tubes are stuggfri-ii, so that those in one row stand 
opposite the spaces between the tubes in the preceding row. 

By this means, all parts of the air-current (which passes 
through horizontally) are brought into contact with the 
tubes and thoroughly heated. 



The base Sir/ioiis. or luaiitrs, are coupled tngethet 
end by flangtd joints. The group of base sections may \ 
divided into two or more parts, each of which may have a 
independent supply and return pipe. Thus, tht 
healer may be used or only a part uf it, as desired. The 
sides of the sections are corrugated so that they interlock 
and leave no open spaces between them. The farther end 
of each section rests upon a roller e, so that they can expand 
and contract freely without straining. The course of the 
steam through the heater is shown by the arrows. 

91. The ordinary vaHeties of vertical-tube radiators 
may easily be adapted to direct-indirect heating. The mode 
of applying a direct radia- 
tor of the Nason or Bundy 
t\ pe to that purpose is 
vh .«n in Fig. 47. The base 
the radiator is enclosed 
\ plates «, so that the fresh 
]i which oomes in through 
I tube b, is compelled to 
I I--S upwards and between 
I hot tubes before it can 
■-( tpe into the room, 


I*roportionln|f Ba*' 

diatlon Surfnoe.— 
rcctlj determine the aaiount 
of radiation required tn 
proptrly warm a given space 
requires the best judgment 
I f a heating engineer. A 
number of rules and for-, 
mill IS fi.r determining radi 
tinii are in use; some are' 
simple and some are compli- 
cated. The following table 

gives the allowance of heating surface commonly supplied 

for ordinary purposes: 







Space to be Heated. 

Bathrooms and living rooms with three \ 
exposed walls and a large amount of glass ^ 
surface * 

Bathrooms and living rooms with two \ 
exposed walls and large amount of glass [- 
surface ) 

Bathrooms and living rooms with one \ 
exposed wall and ordinary amount of glass ,- 
surface ) 

Sleeping rooms i 

Halls I 

School rooms ] 

Churches and auditoriums having large (^ 
cubical contents and high ceilings I 

Lofts, workshops, and factories -J 

Allowance of 

1 square foot for each 
40 cubic feet. 

1 square foot for each 
50 cubic feet. 

1 square foot for each 
60 cubic feet. 

1 square foot for each 

60 to 70 cubic feet. 
1 square foot for each 

50 to 70 cubic feet. 
1 square foot for each 

60 to 80 cubic feet. 
1 square foot for each 

65 to 100 cubic feet. 
1 square foot for each 

75 to 150 cubic feet. 

The foregoing simple table applies to direct radiation 
only. If indirect radiators are used, allow not less than 
50 per cent, more surface. If direct-indirect radiators are 
used, allow not less than 25 per cent, more surface. In 
estimating radiation, make ample allowance for exposure 
of building, materials of construction, and loose doors and 

93. We do not recommend the general use of any 
method of proportioning radiation to the cubical contents 
of the rooms to be heated. The foregoing is presented for 
the convenience of those who may be able to use it with 
good judgment and for ** checking up" purposes. 



4fl STEAM HEATING. g 41 ' 

94. One of the most simple aad probably most correct 
empiric rules used for computing the size of direct radi- 
ators is that originated by Mr. William J. Baldwin, a well- 
known American heating engineer, and is as follows: 

Rules. — "^"^ Dh-id^ tke ihffrrenec btt'^ttH the tempcralure 
at wkKk the rtmm is lo bt kept and that of the coldest outside 
atmespkt-re by the difference between tke temperature of tite 
steam ^fifs and that at ^'hkh you wish to keep tke room, 
ami tke quotient itrili be the square feet, or fraction thereof, 
of plate or ptpe surface to each square foot of glass, or its 
equivalent in wall surface." I 

The qiiantity of heating surface found by this simple rule 
merely compensates for the amount of heat tost by transmis- 
sion through the windows, walls, and other cooling surfaces; 
it does not provide for cold air entering the room through 
loosely fitting doors, windows, etc., and an ample allowance 
must be made for this. Some buildings are so poorly con- 
structed that 50 per cent, or more must be added to the 
amount of heating surface obtained by the above rule, in 
order to ctmnteract the cooling effect of these air leakages. 
A common practice is to add 25 per cent, for buildings of 
ordinarily good construction. Besides this addition for air 
leakage, an ample allowance should be made for rooms 
exposed to cold winds, and this allowance should, if possible, 
be made in the form of an auxiliary radiator to prevent 
overheating the rooms during moderate weather. 

95, Suppose that we have three rooms A, B. and C, as | 
shown in Fig i8, of precisely the same dimensions, and. 
consequently, having the same cubical contents, the rooms 
being each 25 feet long by iii feel wide, with a 10-foot 

Let us also suppose that the halls, or corridors, D and the I 
other rooms in the building will be warmed to a temperature I 
equal to that desired in A, B, and C by other radiators not 
shown : first proceed to find, by rule S. Art. 94. the amo 
<A healing surface required to tnuintain a temperature 
of 70° F. in .-I. /•', and C, assuming thai the radiators will be 



lieatetl by steam having a pressure of a [Kinnds by the gauge, 
the outside teiii|)erature being 10" belmv zero. Let us sup- 

pose that the windows are each fi ft. X 3 ft. and that the 
exposed walls are built of good ordinary brick, lathed and 
plastered inside. 

Let 5 = number of square feet of radiating surface 
required to counteract the cooling effect of the 
glass and its equivalent in exposed wall surface; 
= difference in degrees F. between the desired tem- 
perature of the room and that of the external air; 
' r, = difference in degrees F. between the temperature 
of the heating surface and that of the air in the 
= number of square feet of glass and its equivalent 
in exposed wall surface. 
Then, expressing rule 3. Art. 9-4, as a formula, we get 


When lathed and plastered brick walls are used, as in the 
figure, it is safe to estimate that about 10 square feet of wall 
surface will be equivalent in cooling power to 1 square foot 
of glass; consequently, in this case 

wall surface . i . i _^ 
= equivalent glass surface. 

Let us commence with the room A ; the amount of glass 
surface here is 6 X 3 X 4 = 72 square feet. To this must be 
a.dded the exposed wall surface reduced to a glass equivalent; 

10 (25 + m - n ^ 3^ g ^^^^ j^^ 

Since we assume that the inner walls, floors, and ceilings 
are not cooling surfaces, the only cooling surfaces we have 
to calculate against in the case of A is 7:^ square feet 
-f 37.8 square feet = 109.8 square feet =: s. 

96. The temperature of steam at 5 pounds gauge pres 
sure is 227°, and the difference between 70® above zero and 
lO'' below zero is 70° + 10°; therefore, substituting in the 
formula, we have 

.V= - ^ ^ X 109.8 = 56 square feet, nearly. 

This, however, only counteracts the cooling effect of the 
walls and windows, and to make reasonable allowance for 
air leakage, we will add *Zo per cent, of the above amount, 
or 14 square feet, which gives us 56 + 14= 70 square feet 
of direct radiating surface. 

Now, suppose that we allow 20 per cent of the direct 
radiating surface (70 scjuare feet in this case) for a moder- 
ate c'.\j)osure to winds; the amount of heating surface, that 
i^, I lie size of the radiator that we would place in A^ will 
then i>e 7o -j- 14, or S4 square feet. 

For convenience, we may divide this into two radiators, 
(f having an area of i\i} S(}uare feet and /; an area of 28 square 
feet. This will so divide the radiator surface that one- 
third, «)r •^^s square.' feet, may be used for duty during mild 


weather; two-thirds, or. 50 square feet, for moderate cold 
weather, and the whole, or 84 square feet, for use during 
severe weather. 

In like manner and under the same conditions, we find 
that the sizes of the radiators r, d^ and c should be, respect- 
ively, 40, 82, and 42 square feet. 

As the coldest winds blow in the direction of the arrow, 
we place the 82-square-feet radiator in the left-hand exposed 
corner of the room C. A better distribution of the radiator 
surface in this room would be to make d 42 square feet 
only and place a radiator having 40 square feet between 
the windows towards which the arrow points; this will give 
a more uniform temperature to the room. 

97. The reader will observe that A^ B, and C, which 
are three rooms having the same shape and cubical contents, 
respectively, require 84 square feet, 40 square feet, and 
124 square feet of heating surface, in order to maintain a 
temperature of 70° F. in each while the outer atmosphere 
is 10° below zero, and. he will observe how imperfect must 
be the rule-of-thumb method of proportioning radiators to 
the cubical contents of the several rooms. Baldwin's rule 
should always be used where possible, in preference to the 
method described in Art. 93. 


98. A steam-heating plant really requires but little 
attention. All the engineer or janitor has to do with an 
ordinary system while it is in operation is to insure a 
steam pressure sufficient to produce good heating results. 
In ordinary cases this pressure is from 1 to 5 pounds by the 
gauge. He should inspect the system occasionally, at least 
once a month. In such an inspection he will invariably 
find that some radiator valves leak through the stuffing- 
box. These can easily be repacked without affecting the 
operation of the heating system, for by closing the radiator 
valve the steam pressure is taken off the stuffingbox. lie 



may find that some air vents "spit water" or blow steam 
when they really should be closed, because the radiators on 
which they are screwed arc hot to the extreme end loop. 
These defective air vents should be immediately repaired nr 
adjusted, as each case may require. If the inner parts are 
broken or irreparably defective, the engineer should replace 
the old vent with a new one ; they are too cheap to waste 
much time nn in repairs. The engineer should keep a slock 
of air vents on hand. 

If when steam is on and the radiator valve open, the radi- 
ator diies not heat, it is evident that the air valve is choked 
or otherwise closed so that it will not let out the air. 

99. When a radiator valve is closed and a hissing or 
hammering noise is heard in the radiator, it is evident that 
the valve is not tight. A new disk, preferably of the 
Jenkins variety, should be put on. This requires shutting 
off steam from the riser line to which such a radiator is con- 
nected. If the radiator is connected on the two-pipe sys- 
tem, the return riser must also be shut oflf, otherwise the 
steam pressure may back up the water of condensation into 
the radiator through the returns and flood the building; or 
steam in the return riser will blow through the radiator and 
escape at the radiator valve when the bonnet is unscrewed, 

100. Before replacing a valve stem and disk, it is 
proper to examine the valve seal carefully to see if it has a , 
smooth, true face. If a groove has been ground out or the j 
valve face is rough, it is advisable to grind it or to face it 
smooth and true with a reseating tool. 

101. Before the steam is turned on a heating system in i 
the autumn, all necessary repairs should be made and | 
everything should be clean and ready for firing up at < 
moment's notice or for turning on steam from a power 
boiler or engine exhaust. The heating boilers, if any, 
should have been blown out and cleaned the preceding 
spring, when the system was put out of service for the sum- 
mer. The return mains should all be drained clear at the 
same time. All valves should be examined and repaired, if i 




necessary, during the summer. This will prevent consider- 
able trouble during the winter. 

102. As floors and walls are liable to ** settle," it is 
often necessary to readjust the steam-pipe hangers so that 
the grades of the pipes may be adjusted to prevent water 
hammer. This, also, should be attended to during the sum- 
mer. Indeed, nearly all the attention that a heating system 
of the ordinary character requires is during the summer, 
when the engineer in charge of it usually has some spare 
time. And if a heating system receives proper attention 
during the summer, it should run all winter without repairs. 




Relating to the Subjects 
Treated op in this Volume. 

It will be noticed that the Examination Questions that 
follow have been divided into sections, which have been 
given the same numbers as the Instruction Papers to which 
they refer. No attempt should be made to answer any of 
the questions or to solve any of the examples until that 
portion of the text having the same section number as the 
section in which the questions or examples occur has been 
carefully studied. 


(PART 1.) 


(1) Why cannot a perfect vacuum be formed in the suc- 
tion chamber of a pump ? 

(2) Why can a suction pump at the bottom of a deep 
mine lift water higher than a pump at the surface ? 

(3) Why is it difficult to pump hot water ? 

(4) What do you understand by a direct-acting steam 
pump ? 

(5) What governs the speed of a direct-acting pump ? 

(6) What great objection to the single direct-acting 
steam pump does the duplex direct-acting steam pump 
overcome ? 

(7) What is the peculiarity in the manner of operating 
the steam valves of a duplex direct-acting steam pump ? 

(8) {a) Why is not the ordinary direct-acting pump 
an economical machine ? (b) How may its economy be 
increased ? 

(9) In a Worthington slide-valve duplex pump, how is 
steam retained in the cylinder near the end of the stroke to 
^orra a cushion for the piston ? 

(10) How do the dash relief valves of a Worthington 
steam pump control the length of the stroke ? 

(11) (a) What is the purpose of the so-called cross-ex- 
haust connection in compound direct-acting steam pumps ? 
(^) Explain its action. 

O <> 4 

2 PUMPS. §34 

(12) What is the purpose of the high-duty attachment 
to direct-acting steam pumps ? 

(13) {a) Briefly explain the principle of the high-duty 
attachment, (l?) In what respect is the action of the high- 
duty attachment better than that of a flywheel ? 

(14) In a pump of the Leavitt design, what is gained by 
making the stroke of the plunger shorter than the stroke of 
the engine ? 

(15) Describe the Quimby screw pump in your own words. 

(16) (a) On what does the action of a centrifugal pump 
depend ? (d) To what classes of work are they particularly 
adapted ? 

(17) How are the cranks of duplex double-acting power 
pumps set so as to give a steady .flow ? 

(18) If the supply of power is steady, why is the belt- 
driven pump the most economical pump to use ? 

(19) Why is the plunger pump the most common type of 
pump used in mines ? 

(20) What is a pit pump ? 

(21) What enables the steam to be used expansively in a 
Cornish pumping engine ? 

(22) What advantages does the Bull pumping engine 
possess over the Cornish pump ? 

("23) Mention some of the objections to lift pumps when 
used for mining purposes. 

(24) What terms are usually applied to the suction pipe 
and the delivery pipe of pit pumps ? 

(•-^5) What is meant by a sinking pump ? 

(2i)) What are the advantages of the pulsometer ? 

('27) Mention some of the advantages claimed for the 
Pohle air lift. 

(•28) Briefly describe the principle and action of a differ- 
ent ial pump. 

(•2l>) What is the particular feature of the Riedler express 
pump that allows the pump to be run at such high speeds ? 


(PART 2.) 


(1) (a) How are the plungers of pumps used for moder- 
ate pressures usually packed ? {d) How are they packed 
when used for heavy pressures ? 

(2) Mention two important disadvantages of the inside- 
packed plunger pump. 

(3) What is meant by the valve deck of a pump ? 

(4) What is the object of curving the wings of wing 
valves ? 

(5) Why are air chambers used on the discharge pipes of 
pumps ? 

(6) (a) Briefly describe an alleviator and (d) state why 
they are used instead of air chambers. 

(7) Why are vacuum chambers sometimes required on 
the suction pipe of pumps ? 

(8) In setting up a pump with steam-thrown valves, 
what precautions should be taken in order to have the 
valves work properly ? 

(9) What precautions should be taken in designing the 
suction pipe ? 

(10) {a) What is a foot-valve and (/?) what is its purpose ? 

(11)- Why is it a good plan to use a relief valve on a suc- 
tion pipe that is fitted with a foot-valve ? 


2 PUMPS. § 35 

(12) In what ways may sand and grit held in suspension 
in the suction water be removed before entering the pump ? 

(13) What is the object of placing a check -valve in the 
delivery pipe near the pump ? 

(14) Explain how a water-end by-pass can aid in start- 
ing a compound steam pump. 

(15) Why is it that a pump will sometimes refuse to 
start when air is in the pump chamber and the full pressure 
is on the delivery valves ? 

(IG) Mention some of the causes of loss in efficiency of 
steam pumps. 

(IT) Describe the manner of removing the dirt and grit 
from the piping and cylinder and valve seats of a new steam 

(IS) In starting a new direct -acting steam pump with 
dash relief valves, what precaution should be taken with 
regard to the relief valves ? 

(19) Mention some of the causes of trouble with the suc- 
tion end. 

(20) (cj) In pumpinjx hot water, if the pump works with 
a jerky action, what is the trouble ? (/?) How may this 
jerky action be stopped ? 

(*2l) If the pump pounds at the beginning of the stroke 
when running fast, what is probably the trouble with the 

suction end ? 

i'l'l) ((7) What is the etfect of too little lost motion 
between the valve stem and valve of a duplex pump ? 
(/') What is the effert of too much lost motion ? 

Cio) How may leaks in the suction pipe be detected ? 

(•^4) I low can small pinholes in the delivery pipe be 

stopped U[) ? 

( •*.">) How are air chambers usually tested for leaks ? 

(•i«i) Will an air chamber aid in preventing surging in 
loni; delivery pi[)es ? 

§ 35 PUMPS. 3 

(27) Why is surging in the suction pipes not so serious 
as in the delivery pipes ? 

(28) In pumping a mixture of water and air, how may 
the air be removed from the water before reaching the 
pump ? 

(29) Describe the method of setting the valves of a 
duplex steam pump. 

//. s. V,—3o 


(PART 3.) 


(1) How is the mean effective area of a double-acting 
piston pump found ? 

(2) Explain how the actual discharge of a pump may be 
greater than the piston displacement. 

(3) What is the probable horsepower required to dis- 
charge 1,200 cubic feet of water per hour against a pressure 
of 125 pounds per square inch ? Ans. 15.56 H. P. 

(4) What is meant by the piston speed of a pump ? 

(5) If a pump is to discharge 9-4,000 pounds of water per 
hour, what should be the diameter of the pump plunger, its 
speed being 85 feet per minute ? Ans. 8.22 in., nearly. 

(6) (a) Mention three ways in which the duty of a 
steam pump may be stated and (d) compare their relative 

(7) The plunger of a single double-acting pump is 
24 inches in diameter and the plunger rod is 3^^ inches in 
diameter. The plunger makes 35 strokes per minute, the 
length of stroke being 30 inches. What is the displacement 
in Winchester gallons per hour ? 

Ans. 140,478 gal. per hr. 

(8) A single-acting plunger pump has a plunger 10 inches 
in diameter and a stroke of 30 inches. If the pump makes 


2 PUMPS. § 36 

40 discharging strokes per minute and discharges 48.3 cubic 
feet of water, what is the slip ? Ans. 11.4 per cent. 

(9) If a duplex double-acting pump has plungers 8 inches 
in diameter and makes 35 strokes per minute, how many 
Winchester gallons may the pump be expected to deliver 
per minute the length of stroke being 30 inches ? 

Ans. 182.9 gal. per min. 

(10) If a pump requires 20 pounds of coal to raise 
975 cubic feet of water 140 feet, what is the duty of the 
pump per 100 pounds of coal ? Ans. 42,656,250 ft. -lb. 

(11) Explain how the increased size of pipes and pas- 
sages of large pumps increases the efficiency of the pumps. 

(12) Approximately, how many cubic feet of water per 
minute can a 40-horsepower engine discharge at a height of 
96 feet ? Ans. 154 cu. ft. 

(13) As usually stated, how does the efficiency of a rotary 
or centrifugal pump differ from the efficiency of a recipro- 
cating steam pump ? 

(14) If it is desired to pump water against a pressure of 
350 pounds per square inch, what should be the minimum 
diameter of the steam piston for a pump having a plunger 
9 inches in diameter, the available steam pressure being 
90 pounds per square inch ? Ans. 21.1 in. 

(15) (<?) Mention some of the merits of rotary pumps. 
(/;) For what class of work are they particularly adapted ? 

(IG) About what horsepower will be required to dis- 
charge 48 cubic feet of water per minute, the total lift being 
1S8 feet? Ans. 24.4 H. P. 

(17) What is one serious objection to the use of steam 
driven crank-and-flywhcel pumps for boiler feeding ? 

(18) A double-acting- j)ump has a plunger 2(1 inches in 
diameter and 44 inches stroke. The plunger has a piston 
rod 4 inches in diameter extending through both pump cyl- 
inder heads. During a T^-hour duty trial the total heat 
supplied in the steam to the engine was 1SS,7<)0,300 B. T. U. 
and the pump made 04,S()() strokes. If the average pressure 

§ 36 PUMPS. 3 

indicated by a gauge on the discharge pipe was IGO pounds, 
the average vacuum indicated by a gauge on the suction 
pipe 10 inches, and the difference in level between the cen- 
ters of the vacuum gauge and the pressure gauge 12 feet, 
what was the duty of the pump ? Ans. 110,996,971 ft. -lb. 

(19) If the water piston of a pump is 6 inches in diameter 
and moves at a speed of 85 feet per minute, what will be the 
velocity of the water in the delivery pipe if the latter is 
2k inches in actual diameter ? Ans. 489 ft. per min. 

(20) Estimate the pressure against Tvhich a 35-horsepower 
pump can discharge 62.5 cubic feet of water per minute. 

Ans. 90 lb., nearly. 

(21) Why is it necessary to make the water end of a fly- 
wheel pump heavier than the water end of a direct-acting 
pump ? 

(22) Approximately, at what height will a pump driven 
by a 25-horsepower engine discharge 180 cubic feet of water 
per minute ? Ans. 51.3 ft. 

(23) Find the areas of the suction and discharge pipes 
for a duplex double-acting pump that is to discharge 
66,000 cubic feet of water per hour. 

j Suction pipe 792 sq. in. 
( Delivery pipe 316.8 sq. in. 

(24) Estimate the number of Winchester gallons of water 
a pump of 75 horsepower will deliver per minute against a 
pressure of 150 pounds per square inch. 

Ans. 602 gal. per min. 

(25) If a pump lifted 128,000 cubic feet of water 85 feet 
with 7,2S0 pounds of steam, what was the duty per 
1,000 pounds of dry steam ? Ans. 93,406,593 ft. -lb. 

(26) Roughly estimate the discharge in gallons of a 
double-acting pump with an 8-inch plunger. 

Ans. 208.64 gal. per min. 

(27) What is the principal difference between general- 
service pumps and tank or light-service pumps ? 

4 PUMPS. § 36 

("JS^ As irenerally constructed, what is the distinguishing 
feature of pressure pumps with regard to the plunger 
arrani::emeni ? 

i^i*) If the piston speed is 96 feet and the number of 
delivery strokes 4^ per minute, what should be the length of 
the stroke ? Ans. 2 ft. 

(oO> Mention some of the distinguishing features of the 
mvxiern high -pressure mine pumps. 

(;>1 1 How are the valves of sewage pumps frequently made 
s<^ as to allow large objects to pass through the pump ? 

^o^i Mention one advantage of the electrically driven 
p;imp when used for mining purposes. 

(;v>> What do you understand by dry and wet vacuum 
pumj^ ]* 

^'U^ {J) In compv^>und and triple-expansion direct-acting 
duplex pumps, what is the usual degree of expansion 
obtaine\i ? {}\ How is this ratio sometimes increased ? 

^;io) To what is the high duty of the crank-and -fly wheel 

pump due ? 


(PART 1.) 


(1) How are elevators usually classified with reference 
to the motive power used ? 

(2) What is meant by a corner-post elevator ? 

(3) What do you understand by the term *' drum type" 
of elevator ? 

(4) In the drum type of elevator, how is the rope, as it 
winds upon the drum, prevented from jumping the grooves 
of the drum by its deflection ? 

(5) (a) What do you understand by overbalancing an 
elevator ? (d) What type of elevator cannot be over- 
balanced ? (r) Why? 

(6) What is the advantage of overbalancing an elevator ? 

(7) How may the change in the counterbalancing due 
to the weight of the rope when the car is in different posi- 
tions be compensated ? 

(8) What are the objections to the simple shipper rope 
for operating an elevator ? 

• (9) Into what two classes may safety devices be divided ? 

(10) In what two forms is the motor of the hand elevator 
usually represented ? 

(11) Are hand elevators usually overbalanced or under- 
balanced, if they are balanced at all ? 


i ELEVATORS. § 37 

(l^) Why should all elevators be started and stopped 
gradually ? 

(13) (a) Why are wire ropes used in elevator work made 
with hemp centers ? (^> When should a wire rope be con- 
demned as dangerous ? 

(14) Mention three preparations for lubricating wire 

(15) In fastening the rope to the drum, what precaution 
should be observed in order to reduce the stress at the point 
of fastening ? 

(Ki) Why should not the guides be allowed to become 
gummy ? 

(17) What do you understand by the term belt elevator ? 

(18) Why are worm-geared belt elevators usually over- 
balanced while spur-geared ones are not ? 

(19) How are the limit sto|>s on the shipper rope of belt 
elevators usuallv made ? 

(20) Briefly describe the principle of the most common 
form of motor limit stop. 

(21) What provision is usually made on elevators to pre- 
vent the cable from unwinding should the car stick in its 

descent ? 

(22) In worm-geared elevators how may the end thrust 

due to the use of a worm be avoided ? 

('V-\) What is the maximum speed at which belt elevators 

should be run ? 

(24) In worm-geared elevators what lubricant should be 

uscfj for the worm i)ath ? 

(i.*)) In general, what precautions should betaken in the 

maintenance of belt elevators ? 

(2i;) IC\j)lain briefly the principle of the mechanism for 
reversing the engines of an Otis spur-gear steam elevator. 

(27) What is the general principle of the slack-cable 

safety provided on all steam elevators ? 


(PART 2.) 


(1) Mention (a) the different kinds of electric motors 
used in elevator service, and (d) the service to which each is 
particularly adapted. 

(2) Why should the main switch be closed with all the 
starting resistance in the armature circuit ? 

(3) Briefly describe the operation of the rheostat shown 
in Fig. 1 of the text. 

(4) In the reversible switch shown in Fig. 5 of the text, 
how may sparking at the clips connected to the shunt field 
be prevented when the circuit is being opened ? 

(5) (a) What do you understand by a solenoid rheostat ? 
{/f) What is one advantage of this type of rheostat ? 

(0) What two important conditions must be fulfilled by 
the motor of a direct-connected electric elevator ? 

(7) What are the only alternating-current motors that 
are satisfactory for direct-connected electric elevators ? 

(8) Are direct-connected electric elevators of the drum 
type over or under counterbalanced ? 

(9) In electric elevators, by what different means may 
the brake be operated ? 

(10) (a) Briefly describe the simple controller used by 
the Elektron Manufacturing Company, (d) What is the 



; through such a wid^ 


reason for turning the shipper slienvi 
angle in order to reverse the motor ? 

(11) In the electrical-mechanical brake used by the E 
Iron Manufacturing Company, how is the rapidity of actioir 
of the brake controlled ? 

(12) Briefly describe what takes place when the abow 
elevator is started or stopped, 

(13) Describe the principle of the dynamic bra 
by the Elektron Manufacturing Company. 

(14) (rt) When a dynamic brake is used, why is the field ' 
kept excited after the armature circuit is broken and the 
armature short-circuited ? (6) How is this done in the 
Elektron Manufacturing Company's brake ? 

(15) (d) What is the peculiarity of the step bearing 
used on the A. B. See elevator shown in Fig. 17 of the text ? 
(d) What is the advantage of this arrangement ? 

(ifi) What motor safeties are applied to the A. B. 
elevator ? 

(17) (a) In the Otis single-worm elevator, how 
increased thrust-bearing surface obtained without increasing 
the size of the shaft ? {d) How is the pressure between the 
bearing surfaces equalized ? 

(18) What is the object of the safety magnet used oqJ 
the Otis elevator ? 

(19) (rt) In the Otis high-speed elevators, what provision 
is made for stopping the elevator almost instantly when 
the limits of travel are reached ? (/') How is the operating 
device arranged to prevent accidental reversal of the mote 
in stopping ? 

(20) What is the use of the potential switch made by t 
Otis Company ? 

(21) Briefly describe the potential switch as it is made when 
it only operates when the current falls below the normal. 

(22) (n) Give the general features of the magnet -control 
method of operating elevators, (i) What are its advait 
tages over the rheostat method ? 


§ 38 ELEVATORS. 3 

(23) Explain the operation of the Otis G. S. controller 
when the handle of the car controlling switch is moved to 
the **fast down" position. 

(24) (a) What is the main difference between the Otis G. S. 
magnet controller and the No. 6 controller ? {d) Explain 
the action of the No. 6 controller when the handle of the 
operating switch is moved to the **down " position. 

(25) (a) Describe briefly the operation of the Otis auto- 
matic elevator with older style floor controller when the car 
is at the first floor and the button on the fourth floor is 
pressed. Also, when the passenger enters the car and pushes 
the button to descend to the second floor. (6) Show how 
the circuits are arranged so that the movements of the 
elevator cannot be interfered with when it is already in use. 

(26) Describe briefly the operation and distinctive fea- 
tures of the Sprague- Pratt electric elevator. 

(27) Explain the operation of the Eraser differential- 
speed elevator. 


(PART 3.) 


(1) What are some of the advantages and disadvantages 
of hydraulic elevators ? 

i'Z) (a) What do you understand by a plunger elevator ? 
(d) For what kinds of service are they mostly used ? 

(3) Why cannot plunger elevators be overbalanced ? 

(4) In a balanced plunger elevator, what would happen if 
the car became loose from the plunger ? 

(5) How is it that the controlling valve in a hydraulic ele- 
vator acts as a power control and brake at the same time ? 

(6) How may the rapid descent of a plunger elevator be 
provided against should the controlling valve fail to work ? 

(7) What is the principal advantage of the piston ele- 
vator over the plunger elevator ? 

(8) In vertical piston elevators in which the cylinder is 
always full of water, why is it preferable to put as much of 
the counterweight as is possible directly on the piston or 
piston rods ? 

(9) {a) What is the object of making the water circulate 
from the top to the bottom of the piston in vertical piston 
elevators ? {d) Explain your answer. 


2 ELEVATORS. § 39 

(10) WTiat is the object of placing a relief valve in the 
discharge pipe between the cylinder and the controlling 
valve ? 

(11) (a) What is the purpose of the pilot valve? 
(ff) Why is its use necessary in high-speed elevators ? 

(VZ) Explain the use of the throttle placed between the 
upper and lower pistons of the main controlling valve. 

(13) (n) What do you understand by a double-power 
hydraulic elevator ? (d) Where are they used ? 

(14) In hydraulic elevators in which the ratio of car 
travel to piston travel is very high, the water is admitted to 
but one side of the piston. Why is this done ? 

(l/>) What are the principal advantages of horizontal 
hydraulic piston elevators over vertical hydraulic piston 
elevators ? 

(If)) What do you understand by the terms ** tension 
type" and ''compression type" as applied to horizontal 
hydraulic piston elevators ? 

(IT) In the horizontal tension type, why is the short dis- 
tance required between the sheaves a decided advantage ? 

(15) When a closed pressure tank is used, how is the pres- 
sure within the tank kept practically constant while the 

elevator is in operation ? 

(llO {(j) In what ways may the air escape from closed 

pressure tanks ? {/>) How is it replenished ? 

(•^^0) Briefly describe the Ford regulating valve. 

(•21) How is the Ford regulating valve modified so as to 
operate the switch and rheostat of an electric motor ? 

(22) What is the object of using a by-pass valve to open 
a communication between the suction and delivery pi{>es of 
the pressure pump ? 

(23) If the absorption of the air by the water in the 
pressure tank is excessive, how may it be prevented ? 

§ 39 ELEVATORS. 3 

(24) In filling the pressure tank, how may sufficient air be 
introduced to give the required pressure ? 

(25) If a large quantity of air collects in the cylinder, how 
may it be removed ? 

(26) In what manner will a worn or leaking piston pack- 
ing indicate itself ? 

(27) Briefly describe an effective method of lubricating 
the internal parts of elevator plants. 

(28) In the vertical circulating hydraulic elevator, how 
may the water be removed from the cylinder and circulating 
pipe ? 

(29) Briefly describe the necessary steps in packing a 
vertical cylinder piston from the top. 

(30) If the cylinder of a horizontal hydraulic elevator is 
badly worn, how should the piston be packed ? 

(31) If the packing used is made of cotton, how should it 
be treated to remove the air from the pores ? 


(PART 4.) 


(1) Mention some of the means by which car safeties are 
set in operation. 

(2) (a) For what kind of elevators is the pawl-and-ratchet 
safety suitable ? {d) By what arrangement is the pawl and 
ratchet usually replaced ? 

(3) Why is it necessary to attach each cable to a separate 
wedge-operating lever when a gravity-wedge safety is used ? 

(4) (a) In high-speed elevators, what else besides a broken 
or a slack cable is usually made to operate the safety devices ? 
{6>) By what apparatus is this usually accomplished ? 

(5) Briefly describe how the governor on an Otis elevator 
applies the car safety. 

(6) When a safety drum is used, what is the object of also 
having a governor-controlled brake ? 

(7) Why should not the guides be allowed to become 
gummy ? 

(8) Before unlocking the safety after it has been set, 
what precaution should be taken ? 

(9) If a car has been stopped above the top landing by a 
wedge-safety device, how would you proceed to lower the 


2 ELEVATORS. § 40 

(10) Briefly describe the air-cushion safety and its 

(11) (a) In the air-cushion safety, what should be the 
depth of the pit compared with the height of the lift ? 
{d) In high lifts, how is this depth of pit obtained ? 

(12) (a) Mention some of the objections to solid walls or 
partitions for elevator shafts, (d) If the partitions are not 
carried to the ceilings, how high should they be ? 

(13) Mention some of the requirements of elevator doors. 

(14) In some elevators, how is the car prevented from 
starting before the door is closed ? 

(15) In passenger service, how is the movement of the car 
sometimes indicated to the would-be passengers ? 

(10) For what class of service are escalators particularly 
adapted ? 



(1) Describe briefly the one-pipe system of steam heat- 
ing and explain how the water of condensation is returned 
to the boiler. 

(2) What is the principal difference between the one-pipe, 
two-pipe, separate-return, and drop systems of heating ? 

(3) Mention some of the defects of the one-pipe system 
of heating. 

(4) About what pitch are main steam pipes usually given ? 

(5) In case a horizontal pipe is too long to be given a 
uniform grade for drainage purposes, how can it be drained ? 

(6) (a) Should a long riser be connected directly to the 
top of the steam main by a T ? {d) Why ? 

(7) Explain how a radiator in a one-pipe system may 
become filled with water. 

(8) What is the objection to a return main located above 
the water level ? 

(9) What diameter of main steam pipe is required to 
supply direct radiators having a total heating surface of 
5,000 square feet f Ans. 8-in. pipe. 

(10) What is the usual amount of expansion allowed for 
in steam piping ? 

(11) If a pipe 6 inches in diameter is used, what amoimt 
^^ direct heating surface may be supplied by it ? 

Ans. 2,827.4 sq. ft. 


(12) In what two ways should a system of piping be 
tested before it is covered by plastering or flooring ? 

(13) (a) What is the object of making radiators with 
extended surfaces ? (/f) Has a radiator with extended sur- 
faces any advantage over a radiator having plain surfaces, 
if the air is simply moved by convection ? 

(14) Explain why the most effective form of radiator or 
coil for direct heating is one having a single row of tubes 
placed in a horizontal position. 

(15) What are the advantages of flue radiators with 
regard to efficient heating surface ? 

(1(1) (a) If a flat heating coil is to be used with the row 
of tubes placed vertically, why should not the opposite ends 
of the tubes screw directly into manifolds ? (b) How should 
the coil be constructed ? 

(17) Describe the Nason tube. 

(18) How may a radiator of the Bundy type be adapted to 
direct-indirect heating ? 

(19) In a two-pipe system, why should the return riser 
be shut off when the valve in the steam riser is closed ? 

(20) If it is necessary to place two radiators in one 
room, why is it a good plan to divide the total heating sur- 
face required between the radiators, so that one will be, say, 
twice as large as the other ? 

(21) How many square feet of heating surface should a 
radiator have to heat a room that is 20 feet wide, 30 feet 
long, and 10 feet high ? There are two exposed walls (a side 
and an end) and three windows 3k ft. X 6 ft. The lowest 
outside temperature is 0' F., the temperature of the steam 
used is 225'' P., and the temperature of the room is to be 
TO'" F. The walls are of brick and are lathed and plastered. 
Allow 'M per cent, for air leakage and 25 per cent, for 
exposure to winds. Ans. 78.4 sq. ft. 

(22) If a haniniiMiiii^^ or hissing sound is heard in a radi- 
tor when the valve is closed, what is probably the trouble ? 


('23) If a radiator does not heat when the steam is turned 
on, what is out of order ? 

(24) Where should the air vent be placed on a radiator 
with reference to the steam inlet ? 

(25) (a) What is the principal objection to the ordinary 
air vent ? (d) How may it be remedied ? 

(26) What can you say as to the beneficial results 
obtained by injecting cold feedwater into the receiver of a 
vacuum system to improve the vacuum ? 




included in the 

Examination Questions in this Volume. 

It will be noticed that the Key is divided into sections 
which correspond to the sections in the Examination 
Questions in this Volume. The answers and solutions are 
so numbered as to be similar to the numbers before the 
questions to which they refer. 


(PART 1.) 

(1) On account of mechanical imperfections, air contained 
in the water, and the vapor of the water itself. See Art. 6. 

(2) Because the atmospheric pressure at the bottom of 
the mine is greater than at the surface. See Art. 7. 

(3) Because the increased vapor pressure at the higher 
temperatures counteracts the pressure of the atmosphere. 
See Art. 8. 

(4) A steam pump in which the pressure of the steam in 
the steam cylinder is transferred to the pump piston or 
plunger in a straight line. See Art. 14. 

(5) The difference between the power exerted in the steam 
cylinders and the resistance in the pump. See Art. 14. 

(6) The intermittent motion of the column of water being 
pumped. See Art. 16. 

(7) The steam valves of each pump are drive i by the 
piston rod of the opposite pump. See Art. 16. 

(8) (a) Because it is necessary to carry the full steam 
pressure the full length of the stroke. See Art. 18. 

(d) By compounding the steam end, or by the use of a 
high-duty attachment, or both. See Art. 18. 

(9) There is an exhaust port and steam port for each end 
of the cylinder. The exhaust port is some distance from the 
end of the cylinder, so that the piston covers it before the end 


of the stroke, thus confining some steam in the cylinder I 
act as a cushion. See Art. 2J5. 

(10) The dash relief valves control a passage between the 
steam and exhaust ports and are so set that at the highest J 
speed of the pump there will be sufficient compression to | 
prevent the piston striking the cylinder heads. As the | 
speed becomes slower, the compression remaining the same, 
the piston would stop short of the full stroke, if it were not J 
that the dash relief valves allow the compressed ste; 
escape through the steam port, thus allowing the piston to I 
complete its stroke. See Art. 28. 

(11) (ei) To keep a more uniform pressure in the steam J 
chests of the low-pressure cylinders. See Art. 34. 

(/i) The steam chests of the low-pressure cylinders ; 
joined by a pipe that allows the exhaust from thehigh-pres-.. 
sure cylinders to pass to either of the low-pressure cylinders. | 
When the pressure begins to drop in one low-pressure steam | 
chest, the pressure is highest in the opposite low-pressurej 
steam chest, and as the two steam chests are connected, the. I 
steam pressure is nearly equalized in both. See Art. 34. 

{l:i) It allows the steam to be cut off early in thel 
cylinders, thus allowing the steam to be used expansively. 
See Art. 36. 

(13) (a) The high-duty attachment, as usually made, con- 1 
sists of two compensating cylinders having their plungers! 
attached to opposite sides of the pump crosshead. These 1 
cylinders are connected to an accumulator through hollow i 
trunnions, on which they oscillate as the pump crosshead 1 
moves backwards and forwards. At the beginning of the I 
stroke the plungers are forced into the compensating cylin-F 
ders, thus creating a pressure in the accumulator, but afterl 
the pump crosshead has passed the center of its stroke thff^ 
angle between the compensating plungers and the [ 
piston rod becomes such that the plungers are forced out and! 
thus aid in completing the stroke. Sec Arts. 36 and 37. 

§ 34 PUMPS. 3 

(b) The results obtained are independent of the speed. 
See Art. 38. 

(14) It allows the steam pistons to work at a higher 
speed, which is a decided advantage in many respects. 
See Art. 44. 

(15) The Quimby pump has two shafts placed side by 
side and connected by gears. Each shaft has a right-handed 
and left-handed screw, the right-handed screw of one shaft 
meshing with the left-handed screw of the other shaft. The 
screws fit the casing closely and are a close running fit on 
each other. The water passes through passages in the 
casing to the water ends of the screws and is then drawn 
towards the center by the revolving screws and is discharged 
through the discharge pipe. See Art. 48. 

(16) (a) On the pressure produced by the centrifugal 
force of a quantity of water rotated by the vanes of the 
pump. See Art. 49. 

{b) They are particularly adapted to low heads where 
large quantities of water are to be pumped and also where 
water containing large quantities of mud, sand, and gravel 
is to be handled. See Art. 60. 

(17) 90° apart. See Art. 63. 

(18) Because they get their power with the same efficiency 
as the engine from which they are driven. See Art. 66. 

(19) Because the leakage can be easily stopped and the 
plunger type is best adapted to high pressures. See 
Art. 58. 

(20) A pit pump is a pump having its water end located 
at the bottom of the mine and connected to a steam engine 
or other motor at the surface. See Art. 59. 

(21) The momentum of the pit work is sufficient to com- 
plete the stroke after the steam is cut off; this allows the 
Steam to be used expansively. See Art. 61. 


(23) The heavy walkiny beam and its connections are I 
dispensed with, the first cost is less, there is less friction, [ 
and the advantage of a direct-acting engine is obtained. 
See Art. 63. 

(33) The pump rod reduces the effective area of the pipe | 
and increases the friction of the water. The rods are con- 
cealed and cannot be readily inspected. When the rods or I 
bolts break, it is difficult to recover them. When pumping I 
against a heavy pressure, it is impossible to keep the piston I 
tight. See Art, 67. 

(24) The suction pipe is called the wind bore and the I 
delivery pipe the working barrel. See Art. 68. 

(25) When putting down a new shaft or deepening ; 
old one, the pump used to drain the water from the shaft j 
bottom is called a sinking pump. See Art, 71. 

(26) It has no wearing parts except the valves, which I 
are easily and cheaply repaired. It will work in any posi- 
tion and requires no attention when once started. There i 
are no parts to get out of order and it will pump anything I 
that can get past the valves. See Art. 86. 

(37) It has no moving parts and is not affected by sand I 
or grit. The action of the air purifies the water and cools 
it as it is being pumped. It is also claimed to increase the 
flow of a well. The full area of the well is available for a | 
flow of water. See Art. 88. 

(28) The differential pump has two pistons whose dis- 
placements are in the ratio of 2 to 1. The larger piston I 
works in the suction chamber and the smaller piston in the I 
delivery chamber. When the large piston enters the sue- I 
tion chamber, it forces into the delivery chamber a volume J 
of water equal to its displacement, but at the same time the j 
small plunger has withdrawn from the delivery chamber a 
volume equal to half the large plunger displacement, Thus 
the amount of water actually discharged is equal to the dif- 
ference in the displacement of the two plungers, or equal to 

§34 PUMPS. 5 

the displacement of the small plunger. On the return 
stroke the small plunger discharges an amount equal to its 
displacement and at the same time double the amount of 
water is drawn into the suction chamber. See Arts. 94 
and 95. 

(29) The suction valve, which is positively seated just 
before the end of the suction stroke by a buffer on the 
water plunger. See Art. 10!3. 


(PART 2.) 

(1) (a) With hemp contained in a stuffingbox of the 
ordinary pattern. See Art. 3. 

{b) With a U-shaped leather packing held in a recess in 
the upper end of the pump cylinder. See Art. 4. 

(2) When the packing becomes worn, the heads of the 
pump cylinder must be removed to tighten or renew it, and 
there is no way of detecting leakage when the pump is 
working. See Art. 6. 

(3) The part of the pump chamber that contains the 
valves. See Art. 14. 

(4) To give the valve a partial rotation at each stroke 
of the pump so that it will wear its seat evenly. See 
Art. 20. 

(5) To relieve the pipes and pump of shocks by promo- 
ting a uniform flow of water. See Art. 23. 

(6) {a) An alleviator is simply a plunger working in a 
cylinder through a stuffingbox; the plunger is forced into 
the cylinder by springs or rubber buffers. The cylinder 
communicates with the delivery pipe of the pump and thus 
acts the same as an air chamber. See Art. 28. 

{d) When pumps work against high pressures, the air in 
the air chambers is rapidly absorbed by the water or escapes 
from the air chamber, thus rendering it useless. For this 
reason alleviators are used. See Art. 28. 


2 PUMPS. § 35 

(7) To promote a prompt flow of the water into the 
pump chamber. See Art. 29. 

(8) The foundation surface should not be winding nor 
should the steam or water pipes be sprung into place, else 
the valves will be liable to stick. See Art. 39. 

(9) The suction pipe should be as straight as possible, 
and if bends are necessary they should be of large radius. 
It should be of one size from end to end, and if very long it 
should be somewhat larger than is necessary to keep the 
velocity of flow down to 200 feet per minute. If the lift is 
high, a suction chaijiber and a foot-valve should be provided. 
See Art. 41. 

(10) (a) A foot-valve is a check-valve placed at the lower 
end of the suction pipe and opening towards the pump. See 
Art. 42. 

{d) Its purpose is to prevent the suction pipe emptying 
while the pump is standing and to prevent the water in the 
suction pipe slipping back while running. See Art. 42. 

(11) Because if the suction valves leak or if the priming 
pipe is left open, the full pressure of the delivery water will 
come on the suction pipe, which is usually not designed to 
withstand such a high pressure. See Art. 43. 

(12) By means of a settling chamber, a suction basket, a 
strainer, or a special form of strainer consisting of perforated 
plates placed in the suction pipe near the pump cylinder. 
See Arts. 44 and 45. 

(13) To relieve the pump of pressure when starting up, 
so that it will take hold of the water more readily, and to 
hold back the water in case of repairs. See Art. 46. 

(14) By opening the by-pass the pressure on the plungers 
can be relieved for a sufficient number of strokes to allow 
steam to enter tin* low-pressure cylinder, thus rendering the 
full power of the steam end available for pumping. See 
Art. 48. 

§ 35 PUMPS. 3 

(15) The air is not dislodged but only compressed and 
expanded again with the motion of the piston ; thus no 
vacuum is formed and the pump will not start. See 
Art. 62. 

(16) Wear, improper adjustments, wrong timing of the 
movements of the steam valve, leakage^ lack of alinement, 
and foreign matter in the suction and foot-valves and suc- 
tion and delivery pipes. See Art. 68. 

(17) The pistons, valves, and cylinder heads are removed, 
and as the steam pressure rises in the boiler it is allowed to 
blow through, thus thoroughly cleaning the piping. Before 
the working pressure is reached, the stop-valves are closed 
and the cylinder heads put on and the stuffingboxes closed, 
leaving the pistons and valves still out of the cylinders. The 
steam at full working pressure is then turned on, which 
thoroughly removes all dirt and grit from the valve seats 
and cylinders. Any dirt found in the corners of the cylin- 
ders should then be removed by hand. See Arts. 63 
and 64. 

(18) The dash relief valves should be closed in order to 
keep the piston as far from the cylinder heads as possible. 
See Art. 73. 

(19) Leaks at the joints or along the suction pipe or in 
the pump chamber, which may be caused by imperfect con- 
nections, leaky chaplets, shifted cores, blowholes, corrosion, 
or cracks from frost. See Art. 76. 

(20) (a) The lift is too high for the temperature of the 
water. See Art. 77. 

{d) By decreasing either the lift or the temperature. 
See Art. 77. 

(21) The pump chamber is not filling and the plunger is 
striking the incoming water on its return stroke. See 
Art. 78. 

(22) (a) Short stroking. See Art. 83. 

(d) The piston will strike the heads. See Art. 83. 

H. S. v.— 32 

4 PUMPS. § 35 

(23) By the ear, by the flame of a candle, or by stopping 
the lower end of the suction pipe and putting a pressure of 
40 or 50 pounds per square inch on it. See Art. 85. 

(24) By spreading a thick layer of red-lead putty over 
the leaks and then wrapping several layers of canvas covered 
with red-lead putty on both sides tightly about the pipe. 
See Art. 88. 

(25) By closing all openings and then pumping air into 
them until the working pressure is reached. If the chambers 
are tight, the air pressure should show no reduction in 
24 hours. See Art. 90. 

(26) No ; they probably aggravate the trouble by forming 
a cushion from which the column of water rebounds. 
See Art. 97. 

(27) Because the direction of the force resulting from 
surging in the suction pipe is in the natural direction of 
flow of the water and simply tends to open the pump valves, 
while the shock due to surging in the delivery pipe comes 
against the valves and must be withstood by the machinery. 
See Art. 99. 

(2S) By connecting an air pump to the suction air 
chamber. See Art. 102. 

(•20) !Move the pistons until they strike the cylinder 
heads and make a mark on the piston rod at the end of the 
steam-end stutfinLcl)()x [^land. Move the pistons until they 
strike tlie opposite cylinder heads and make another mark on 
the ])iston rod. Then make a mark half way between these 
two marks and move the pistons until these central marks 
('(.nv' even with the end of the stuffingbox gland. Now set 
the valves central over the ports and adjust the locknuts so 
as t<» allow the same lost motion on each side of the valve. 
See Art. 103. 


(PART 8.) 

(1) The mean eflfective area is equal to twice the piston 
area diminished by the area of the piston rod, and the differ- 
ence divided by 2. See Art. 4. 

(2) When the suction and discharge pipes are long and 
the lift moderate, there may be sufficient energy imparted 
to the column of water during the discharge stroke to keep 
it in motion during the return stroke. Under these condi- 
tions the actual discharge may be larger than the displace- 
ment. See Art. 8. 

(3) Reducing the volume per hour to pounds per min- 
ute, we have 

1/200 X 02.5 , ,,_ , . ^ 
— = 1,250 pounds per mmute. 

Applying rule 4, Art. 16, we have 

//.= ^^^^^^=15.56H.P. Ans. 

(4) The number of feet traveled per minute by the 
plunger when discharging water. See Art. 20. 

(5) Reducing the weight of water discharged per hour 
to cubic feet discharged per minute, we have 

oronro = ''■'' '^"^•^ ''''- 


2 PUMPS. §36 

Applying rule 9, Art. 33, we get 

, /229 X 25.07 o ^^ . , . 

a = ^i / — = 8.22 in., nearly. Ans. 

(6) {a) The duty may be stated as the number of foot- 
pounds of work done per 100 pounds of coal burned, or per 
1,000 pounds of dry steam, or per 1,000,000 B. T. U. sup- 
plied. See Arts, 35, 36, and 38. 

(b) Duty based on the coal consumption gives an idea of 
the coal required by a pump of a given type for the per- 
formance of a given quantity of work, but it does not give 
reliable results when the duty of pumps of different types 
working under different conditions are to be compared. 
The basis of 1,000 pounds of dry steam is better adapted to 
duty trials, but it is open to the objection that the pressure 
of the steam is not taken into consideration. The heat-unit 
basis is the most scientific and the most accurate for com- 
parative purposes, as the duty is based on the exact amount 
of heat energy consumed by the pump. See Arts. 35, 37, 
and 38. 

(7) The mean effective area of the plunger is 

24" X .7S54+ (24' X .7854- - 3^ X .7854 ) 

= 447.58 square inches. 

Applying rule 1, Art. 3, we have 

., 80 X 447.58 X 35 ,,.,., , 
At, = ^.Ji ~ 2,441.3 gal. per mm., 

or 2,441.3 X 00 = 140,478 gal. per hr. Ans. 

(8) By rule 1, Art. 3, the displacement is 

30 X 10'^ X .7854 X 40 ^^ ^^ .. , 

-^ = 54.54 cubic feet. 

1 , < *v 8 

By rule 2, Art. 8, the slip is 

(54.54- 48. :j) X 100 ^^ ^ ^ . 

^ ^ = 11.4 per cent. Ans. 

t)4. o4 

§ 3C PUMPS. 3 

(9) The piston speed is f^ X 35 = 87.5 feet per minute. 
Applying rule lO, Art. 23, we have 

y^ 8 X 87.5 ^ A A a £i. 

D = — t;— — = 24.45 cu. ft. per min., 

24.45X1,728 ,q.. ^ , . . 

or jr— = 182.9 gal. per mm. Ans. 

(10) The weight of water pumped is 975 X 02.5 
= 00,937.5 pounds. By rule 14, Art, 34, we get 

^ 100 X 00,937.5 X 140 ,^ ^_ ^^^ ^^ ,, . 
D = '-— = 42,050,250 ft.-lb. Ans. 

(11) Increasing the size of pipes and passages reduces 
the relative amount of friction surface exposed per unit 
volume of water delivered, thus increasing the efficiency. 
See Art. 49. 

(12) By rule 6, Art. 17, we have 

JF=^=^-^«V''-*« = 9,625 lb., 

or * ^ = 154 cu. ft. per min. Ans. 

02. 5 ^ 

(13) The efficiency of a rotary or centrifugal pump is 
the efficiency of the pump itself and not of the pump and 
engine, as in the case of a steam pump. See. Art. 50. 

(14) The area of the plunger is 9' X .7854 = 03.02 square 
inches. By rule 13, Art. 28, we get 

, /l.S X 03.02 X 350 ^,, , . . 

"• " V 90 "^ ^"* * 

(15) (a) Rotary pumps are light, simple, and inexpensive, 
and occupy relatively but little space for their capacity. 
They require but little or no foundation. See Arts. 55 
and 56* 

(V) They are particularly adapted to pumping water 
holding soft material in suspension. See Art. 55. 

4 PUMPS. § 36 

(16) The weight of water to be pumped per minute 
is 48x62.5 = 3,000 pounds. Applying rule 3, Art. 14, 
we get 

„ 3,000 X 188 ^, , TT T^ A 
^- 23,100 =^^^'-^H.P. Ans. 

(17) They cannot always be run slow enough to suit the 
demand without stopping on the centers. 

(18) The mean effective area of each end of the plunger 
is 26' X .7854 - 4" X .7854 = 518.36 square inches. The pres- 
sure corresponding to a vacuum of 10 inches is / = 10 
X .4914 = 4.91 pounds per square inch, and the pressure cor- 
responding to a difference in level of 12 feet is ^ = 12 X .434 
= 5.21 pounds per square inch. The stroke is f J = 3| feet. 
Applying rule 10, Art. 44, we get 

^ _ 1,0 00,000 X (160 + 4.91 + 5.2 1 ) X 518.36 X 3| X 64,800 

= 110,996,971 ft. -lb. Ans. 

(19) The area of the piston is 6* X .7854 = 28.27 square 
inches and the area of the delivery pipe is 2J^' X .7854 
= 4.91 square inches. By rule 18, Art. 52, we get 

V = — = 489 ft. per mm. Ans. 

(20) Reducinj^ the cubic feet of water to be delivered to 
pounds, we have ('.•>. 5 X 02.5 = 3,906.25 pounds. Applying 
rule 7, Art. 18, we have 

,, 10,043 X 35 ^^^ ,, . . 

7^= . , ^^ = 90 lb., nearly. Ans. 
;5.*H)<;.25 ' ^ 

i't\) The velocity of discharge of a flywheel pump is 
variable throui^hout the stroke; thus shocks are produced 
that make it neressarv to use a heavier water end than 
would he used for a direct-acting pump, where the velocity 
of discharge is practically constant. See Art. 88. 

{'VI) Reducing the volume of water discharged to pounds, 
we have 180 X 0*^.5 — 11,250 pounds. By rule 5, Art. 16, 

we i^et 

§ 36 PUMPS. 5 

, 23,100 X 'Z5 „ „f^ . 

^ = ^t;26o- = ''-^ ^'- ^"^- 

(23) Reducing the water discharged to cubic feet per 
minute, we have *VV~^ = 1,100 cubic feet. Applying 
rule 17, Art. 51, we get for the suction pipe 

U4X 1,100 _ 
"^^^ "200, 

and for the delivery pipe 

- 144x1,100 __ o . . 

A = — — ^ = 316.8 sq. in. Ans. 


(24) By rule 8, Art. 19, we get 

j,r 10,043 X 75 ^ ^,, „ ,, 

If = ^^^ = 5,021.5 lb, per mm., 


or Q ' = 602 gal. per min. Ans. 

o. «i4 

(25) Reducing the volume of water to pounds, we have 
128,000 X 62.5 = 8,000,000 pounds. Applying rule 16, 
Art. 36, we have 

n = ^'^"^ ^ ';?,?"" ^ '^ = 93,406.593 ft-lb. Ans. 

(26) By rule 11, Art. 24, we get 

Dg = 3.26 X 8" = 208.64 gal. per min. Ans. 

(27) The principal difference is in the relative sizes of 
the steam and water cylinders, the steam cylinder being 
proportionally much larger for the general-service pumps 
than for the light-service pumps. See Art. 67. 

(28) The distinguishing feature is the four single-acting 
plungers working in the ends of the water cylinders. See 
Art. 70. 

(29) By rule 12, Art. 26, we have 

L = 11 = 2 ft. Ans. 

(30) Outside-packed plungers; strong circular valves 
independent of one another, but bolted to the working 

6 PUMPvS. § 36 

chamber, to the suction and delivery pipes, and to one 
another. All parts are made so that they can be easily 
renewed and sometimes the whole water end is made of some 
acid-resisting bronze or is made of iron or steel and lined 
with some acid-resisting material. See Art. 71. 

(M) The valves are frequently made in the form of large 
leather-faced door or flap valves, giving the full area of the 
pipe. See Art. 79. 

(32) Many various sizes of pumps can be placed about 
the mines and driven from an economical generating unit at 
the surface. See Art. 83. 

(33) Dry vacuum pumps are those that handle air only, 
while wet vacuum pumps handle both air and water. See 
Art. 86. 

(34) {a) The degree of expansion usually obtained is a 
little more than the ratio of the high-pressure cylinder to 
the low-pressure cylinder. See Art. 87. 

(d) This ratio is sometimes increased by making the 
reciprocating parts heavy and running the pump at some 
fixed minimum speed such that the inertia of the parts will 
complete the stroke when the steam is cut off in the high- 
pressure cylinder before the end of the stroke. The degree 
of expansion may also be increased by the use of a high-duty 
attachment. See Art. 87. 

(35) The high duty is mainly due to the degree of expan- 
sion that can be obtained, and also to the ease with which 
all the refinements necessary for high duty can be applied. 
See Art. 89. 


(PART 1.) 

(1) They are classified as hand-power elevators, belt 
elevators, steam elevators, electric elevators, and hydraulic 
elevators. See Art. 3. 

(2) An elevator in which the upright posts of the car are 
placed on diametrically opposite corners. See Art. 4. 

(3) One in which the transmitting devices include a drum 
and rope. See Art. 5. 

(4) By guiding the rope on the drum by means of a 
sheave that is caused to follow the motion of the rope back 
and forth across the drum. See Art. 6. 

(5) (a) Making the counterweight heavier than the full 
weight of the car. See Art. 11. 

(d) Hydraulic elevators. See Art. lO. 

(c) Because the power can only be applied on the up trip. 
See Art. lO. 

(G) If the elevator is overbalanced by an amount equal to 
the average load, no power except that necessary to start 
the machinery and overcome frictional resistances will be 
required when lifting the average load, thus enabling a 
smaller motor to be used. See Art. 11. 

(7) By using a chain attached to the bottom of the car 
and extending either to the bottom or to the middle of the 
shaft way, where it is fastened. In the former case the 


2 ELEVATORS. § 37 

chain must have the same weight per unit length as the rope 
to be balanced ; in the latter case it must be twice as heavy 
per unit of length. See Art. 13. 

(8) There is no means of telling the exact position of the 
controlling device, hence it cannot be applied to motors 
requiring delicate adjustment. Also, the sliding of the rope 
through the hand of the operator is inconvenient and may 
be dangerous. See Art. 17. 

(9) Motor safeties and car safeties. See Art. 36. 

(10) By a shaft actuated through a rope sheave and an 
endless rope or by a crank driving a windlass. See Art. 39. 

(11) They are generally overbalanced. See Art. 33. 

(12) To avoid undue stress being thrown on the 
machinery. See Art. 39. 

(13) {a) To make them more pliable and thus more dura- 
ble. See Art. 44. 

(b) When the wires commence cracking. See Art. 45. 

(14) Equal parts of linseed oil and Spanish brown or 
lampblack. Seven parts of linseed oil and three parts of tar 
oil. Cylinder oil, graphite, tallow, and vegetable tar also 
make a good preparation. See Art. 46. 

(15) The rope .should encircle the drum several times 
when the elevator is in its lowest position. See Art. 50. 

(10) Because the elevator will be given a jerky motion 
and the car may then drop sufficiently far in some cases to 
break the rope. See Art. 51. 

(17) An elevator driven directly by belts from line shaft- 
ing. See Art. 5*4. 

(18) Overbalancing^: spur-i^^eared machines greatly in- 
creases the jcrkincss of motion, while it has little influence 
that wav on worm-ii:cared ones. See Art. 54. 

§ 37 ELEVATORS. 3 

(19) By clamping knobs or buttons to the shipper rope 
in such positions that the car will strike them and cause the 
belt to be shifted automatically when it reaches the limits of 
its travel. See Art. 58. 

(20) The most common form of motor limit stop consists 
of a gear-wheel having a thread cut in its hub and working 
loosely on a thread cut on an extension of the drum shaft 
or on a shaft positively driven from the drum shaft. This 
gear meshes with another of wide face attached to the 
shipper sheave, and as it is prevented from turning by the 
wide-faced gear, it travels back and forth on its shaft, its 
position depending on the position of the car. Should the 
car overrun its limit of travel in either direction, jaws on 
the hub of the loose gear engage with jaws fastened to 
the threaded shaft and thus the loose wheel is rotated. This 
causes the wide-faced gear to revolve and turn the shipper 
sheave, which reverses the motion of the elevator. See 
Art. 59. 

(21) Some form of slack-cable safety is provided that is 
operated by the slack cable and reverses the direction of 
motion of the drum. See Art. 60. 

(22) By using two worms on the same shaft, one being 
right-handed and the other left-handed. The two worms 
mesh with two worm-gears that are in mesh with each other. 
See Art. 62. 

(23) 00 feet per minute. See Art. 74. 

(24) Castor oil or a mixture of 2 parts of castor oil and 
1 part of the best cylinder oil. See Art. 71. 

(25) The limit stops should be frequently tested; the 
brake should be adjusted whenever the car settles at the 
landings; the belts should not be allowed to become slack 
and they should not be subjected to the influence of steam, 
water, or oil. All bearings should be kept well lubricated, 
particularly the step bearing, and the worm-gearing oil bath 
should be occasionally renewed. See Arts. 66 to 7!8« 

4 ELEVATORS. § 37 

(26) The principle of the reversing mechanism is that 
by means of a reversing valve the valves of the engine can 
be changed from direct to indirect valves. See Art. 80. 

(27) It consists of a rod extending across the under 
side of the winding drum and so arranged that the loose cable 
striking it will cause a spring or weight to be released, 
which will cause the steam to be shut off. See Art. 94. 


(PART 2.) 

(1) (a) Continuous-current constant-potential shunt- 
wound single-speed motors, alternating-current motors, 
polyphase-synchronous motors, and induction motors. See 
Art. 6. 

(d) For belt-shifting elevators, the continuous-current 
constant-potential shunt-wound single-speed motors are used. 
If the motor runs continuously, any kind of alternating-cur- 
rent motor may be used, but if the motor is to be started 
and stopped frequently, polyphase-synchronous motors or 
induction motors are used. See Art. 5. 

(2) To prevent a damaging rush of current in starting 
the motor. See Art. 6. 

(3) The contact bar of the rheostat shown in Fig. 1 of 
the text is attached to a rack that is driven by a two- toothed 
pinion, the pinion being on a shaft that is, in turn, driven 
from the main shaft of the motor. When the motor is 
started, the rack is drawn into contact with the pinion by 
means of an electromagnet that is energized by a coil in 
shunt with the motor circuit, and as the contact bar rises, 
it gradually cuts out the resistance. As soon as the current 
is broken, the contact arm drops back and the rack springs 
out of gear. See Art. 7. 

(4) By connecting across the shunt a series of incandes- 
»t lamps having a combined voltage of from 6 to 8 times 

of the line current. See Art. 11* 


2 ELEVATORS. § 38 

(5) {ti) A rheostat in which a solenoid is used to operate 
the arm that cuts out the resistance. See Art. 13. 

{b) It enables the rheostat to be mounted separate from 
the switch and the switch alone to be operated by the hand 
rope. See Art. 13. 

(6) It must have a strong torque and it must get up 
speed rapidly, though gradually. See Art. 17. 

(7) Two-phase or three-phase induction motors. See 
Art. 17. 

(8) Overbalanced. See Art. 19. 

(9) By mechanical, electrical-mechanical, or wholly elec- 
trical attachments. See Art. 31. 

(10) {a) The controller consists of a double-throw switch 
attached to the hub of the shipper sheave and a solenoid 
rheostat placed near the machine. A casting forming one 
part of the switch is bolted to the frame of the machine and 
carries four sets of clips to which the line, field, armature, 
solenoid, and electric-brake connections are made. By rota- 
ting the shipper sheave, the switch blades attached to it 
may be brought into contact with either of the two sets of 
clips, thus reversing the motor. See Art. 27. 

(b) It gives the rheostat arm time to fall back into its 
starting position before the current in the armature can be 
reversed, and it also helps to reduce sparking and flashing 
at the clips. See Art. 27. 

(11) By means of a dash pot. See Art. 28. 

(12) When the shipper sheave is rotated, the brake mag- 
net is energized and slowly releases the brake. The solenoid 
is also energized and cuts out the resistance from the arma- 
ture circuit at such a rate that when the motor is up to 
speed, the resistance is entirely cut out. When the circuits 
are broken, the brake is applied and the resistance arm 
drops back to its original position. See Art. 30. 

(13) The principle of the dynamic brake is that the 
motor is made to act as a dynamo by means of a variable 


resistance so arranged that the armature is short-circuited 
through it immediately after the line circuit is broken. This 
has the effect of slowing the motor down quickly but grad- 
ually. As the motor slows down, the resistance is gradually 
cut out, thus making the stop still more gradual. See 
Art. 31. 

(14) (a) In order to make the motor act as a dynamo or 
brake. See Art. 33. 

(d) The field in this case is kept constantly excited, and 
in order to use less current a resistance is inserted in the 
fields that are short-circuited when the elevator is started, 
thus giving the full torque available. When the elevator is 
stopped, the resistance is cut in, leaving the field current 
strong enough to get a dynamic-brake effect. See Art. 33. 

(15) (a) Both steps are on the same end of the shaft. 
See Art. 40. 

{d) It is easily accessible for inspection or adjustment. 
See Art. 40. 

(16) The usual traveling-nut, limit-stop, and clutch- 
operating slack-cable safety, and also a limit switch that 
brakes the current through the armature and brake solenoid 
at the limits of the car travel. See Art. 43. 

(17) {a) By dividing the pressure between the end sur- 
face of the shaft and the ring-shaped surface of a bushing 
placed around the shaft. See Art. 63. 

{d) By means of two small equalizing levers, which dis- 
tribute the pressure equally over both surfaces. See Art. 53. 

(18) To automatically apply the brake should the current 
be interrupted in the system. See Art. 59. 

(19) {(j) The brake is so arranged that it will be set in 
action by the limit stop much quicker and more effectively 
than by the ordinary device. See Art. 58. 

(d) The tripping device is given considerable lost motion, 
or backlash, which allows the motor to be stopped without 
danger of reversing it. See Art. 60. 


(30) To break the main current and thus release the | 
safety brake when the current falls below the normal i 
when the current becomes excessive. See Arts. 61 and G% I 

(21) The potential switch has three blades with three I 
corresponding double clips, of which the first two are c 
nected to the line wires and the third lo a wire leading lo I 
the starting resistance. The first two blades are connected J 
to the motor circuit and one of them is also connected to I 
the third blade. An electromagnet placed in shunt across I 
the line and in series with the safety-brake magnet holds the I 
first two blades in contact with their corresponding clips,! 
A spring counteracts the magnet and causes the first two I 
blades to leave their clips and the third blade to engage its J 
clip when the current in the magnet windings falls below the | 
normal, See Art. 61. 

{'i'i) {a) In the magnet-control system of operating elec- , 
trie elevators, the starting, stopping, and reversing of the I 
motor and the cutting out of the starting resistance i 
accomplished by a series of electromagnetic switches that I 
are controlled by a car-operating switch on the car. The J 
switches are usually in the form of solenoids or electromag- i 
nets that operate whenever current is made to flow through j 
them by means of the car -operating switch. See Arts, 68 I 
and 69. 

{/•} It avoids the necessity of using the sliding arm and I 
numerous contact plates that are necessary with a rheostat j 
and that always give more or less trouble due to burning 
and cutting, especially with heavy currents. See Art. 69. 

(23) Give a description similar to that contained in 1 
Art. 81. The action is the same as there described, except I 
that the main switches operate so as to make the current I 
flow through the armature in the reverse direction. 

(24) (a) The main difference lies in the construction of i 
the switches, the principle of operation being practically I 
the same. Each switch consists of a solenoid arranged s 

as lo draw up a core or plunger to which contact disks arc. | 

§ 38 ELEVATORS. 5 

attached and which make the required connections by being 
brought into contact with fixed fingers mounted on the 
switchboard. See Art. 85, 

(b) The explanation required is similar to that contained 
in Art. 88, except that the operating switch is supposed to 
be on the down position and, consequently, the direction- 
controlling switches operate so as to reverse the motor. 

(25) (a) A description similar to that contained in 
Arts. 96, 97, 98, and 99 is required. This can be made 
considerably shorter than that given in the text, but the 
path of the operating current and the main current should 
be described. 

(*) See Art. 99. 

(26) See Art. 102. 

(27) See Art. IIO. 

H, S. y.—33 


(PART 3.) 

(1) Hydraulic elevators are safe, reliable, smooth-acting, 
and are under perfect control. The wearing parts are few 
and are easily and cheaply replaced. On. the other hand, 
they require considerable space and usually require the 
installation of steam pumps, reservoirs, etc., which makes 
them expensive. See Art. 1. 

(2) (a) An elevator in which the car is placed directly 
on top of the piston or plunger. See Art. 3, 

(6) For freight and passenger service for short lifts. 
See Art. 2. 

(3) Because the power acts only on the up stroke of the 
elevator. See Art. 6. 

(4) The car would be jerked upwards against the over- 
head work. See Art. 5, 

(5) As a power control it shuts off the power at the will 
of the operator, and as a brake it shuts off the water grad- 
ually by throttling. See Art. ?• 

(6) By putting in the discharge pipe a throttle valve con- 
trolled by the pressure corresponding to the velocity of the 
exhaust. See Art. 10. 

(7) The cylinder can be made much shorter by intro- 
ducing multiplying sheaves, and thus the water used per 
stroke is greatly reduced. See Art. 11, 


2 ELEVATORS. § 39 

(8) Because the car will not tend to teeter up and down 
when the power is suddenly cut off if the counterweights 
are arranged in this manner. See Art. 15, 

(9) (a) To make the effective pressure on the piston the 
same at all points of the stroke. See Art. 16, 

(6) When the piston is at the top of the cylinder, the 
weight of the water above it is practically nothing, while 
the column of water below it exerts a suction corresponding 
to the height of the column, as long as the column is not 
higher than 34 feet. As the piston moves down, the 
weight of water above it increases, while the suction below 
it decreases by a corresponding amount. Thus the pres- 
sure remains constant for all positions of the piston. See 
Art. 16. 

(10) To avoid the water ram that would occur if the 
controlling valve was suddenly closed when the piston was 
descending. See Art. 18. 

(11) (a) To control the opening and closing of the main 
controlling valve. See Art. 19. 

(d) Because in high-speed hydraulic elevators the con- 
trolling valve cannot be operated directly without danger 
of producing violent shocks in starting or stopping. See 
Art. 19. 

(12) The throttle, if properly adjusted, deadens the noise 
occasioned by the circulating water and serves as a brake 
in descending. It also prevents the water from rapidly 
flowing out of the circulating pipe should the supply pipe 
break. See Art. 23, 

(13) (a) An elevator that can be connected either to a 
high-pressure or a low-pressure tank at the will of the 
operator. See Art. 25, 

(d) In office buildings where it is only occasionally neces- 
sary to lift heavy loads. Sec Art. 25, 

(14) Because the greater the ratio, the shorter the cylin- 
der and hence the less becomes the head of water to be 

§ 39 ELEVATORS. 3 

counterbalanced, thus allowing the non-circulating system 
to be used. See Art. 26. 

(15) They occupy less valuable floor space and are more 
accessible than the vertical type. See Art. 28. 

(16) The terms apply simply to the condition of the 
stress in the piston rod, that is, to whether the rod is in 
tension or compression when the car is going up. See 
Arts. 29 and 30. 

(17) Because the whipping of the ropes is very much 
reduced and thus teetering of the car is prevented to a 
great extent. See Art. 30. 

(18) By having the tank partly filled with air, which 
expands as the water is withdrawn. See Art. 39. 

(19) {a) By leakage or by absorption in the water. See 
Art. 39. 

(d) By a vent in the suction pipe or by a separate air 
pump. See Art. 39. 

(20) The Ford regulating valve consists of a spring- 
actuated steam valve that is operated by a small water pis- 
ton working in a cylinder that is connected to the pressure 
tank by a small pipe. As the pressure in the tank rises and 
falls the water piston rises and falls also, thus causing the 
steam valve to open or close. See Art. 43. 

(21) The spring-actuated steam valve is replaced by a 
small water piston valve that controls, by its movement, the 
amount of water allowed to enter or leave an auxiliary 
cylinder, to the piston of which is connected a lever opera- 
ting the switch and rheostat. By this means a comparatively 
large movement is obtained. See Art. 44. 

(22) To allow the pump to run continuously. See 
Art. 47. 

(23) By introducing into the tank a layer of heavy oil 
about 4 inches thick. See Art. 52. 

(24) By opening the vent in the suction pipe when the 
tank is about half full or by filling the tank two-thirds full 


and then pumping up the required pressure by the auxiliary 
air pump, if one is attached. See Art. 51. 

(25) Run the car to the top and set the controlling valve 
for going down. While the car and valve are in this posi- | 
tion, open the air cock and allow the air to escape. See i 
Art. 53. 

(ac) By a groaning in the cylinder or liy the car settling I 
at the landings. See Art. 54. 

(27) Connect the exhaust-steam drips from the pump J 
with the discharge tank, thus allowing the cylinder oil to be | 
pumped with the circulating water, by which means all the [ 
internal parts of the plant are lubricated. See Art. 57. 

(28) When the car is down, open the air cock and drain- 
pipe valve and then throw the valve for going up. Thia.] 
will drain the cylinder. To drain the circulating pipe, 
throw the valve for going down. See Art. 60. 

(2») Run the car to the bottom and close the stop-valve I 
in the supply pipe. Open the air cock at the head of the t 
cylinder and drain the water in the cylinder down to the top I 
of the piston. Remove the cylinder head, and if the pis- , 
ton is not near enough to attach a small tackle to the 1 
main cables and draw it up within reach. Now, remo' 
piston follower and renew the packing. After replacing 1 
the piston follower, let down the piston to its proper posi- 
tion and replace the cylinder head. Place the operating j 
valve on the center, open the supply-pipe valve, and as soon j 
as the air has escaped close the air cock and the elevai< 
ready to run. See Art. G7. 

(30) The first and last ring of packing should be of j 
rubber cut about 1 inch longer than the circumference < 
the cylinder. The remaining rings should be of fibroui 
packing. See Art. C9. 

(31) It should be soaked in boiling tallow for several <| 
hours. See Art. 72. 


(PART 4.) 

(1) The breaking of the cable or cables, the temporary 
sticking of the car, allowing the cable to become slack, or 
excessive speed of the car. See Art. 1. 

(2) (a) For slow-speed elevators. See Art. 3. 

(d) By a wedge that acts between the guides and guide 
shoes. See Art. 3. 

(3) In order to operate the safety should any one of the 
cables break, stretch, or become slack. See Art. 5, 

(4) (a) Excessive speed of the car. See Art. 6. 

(6) By means of a centrifugal governor driven by a rope 
attached to the car, the safety devices are brought into 
action when the speed exceeds a certain limit. See Art. (>• 

(5) The governor is operated by a rope that is attached 
to the finger shaft of the safety device. When the speed 
becomes excessive, the governor balls fly out and operate a 
clutch consisting of two eccentrics that grip the rope and 
hold it firmly. Consequently, as the car descends the ten- 
sion on the rope becomes great enough to rotate the finger 
shaft and thus operate the safety device. See Art. ?• 

(G) To insure a gradual fall of the car, thus giving the 
safety time to act, should the hoisting rope break. See 
Art. 12. 

(7) Because they might cause the safety wedges to stick 
and be thrown into action. See Art. 1(>. 


2 ELEVATORS. § 40 

(s) All slack in the hoisting cables should be taken up. 
See Art. 17. 

(y) Remove the limit-stop button on the shipper rope 
and raise the car enough to unlock the wedges. If this 
cannot be done, the car may be lifted by a tackle. See 
Art. 17. 

(10) The air-cushion safety consists of an extension of 
the hoistway below the lowest landing in the form of a pit. 
The cross-section of the pit is such that the car is gradually 
brought to rest by the escape of the air contained in the 
pit through the space between the sides of the car and the 
sides of the pit. See Art. 18. 

(11) (a) The depth of the pit should be about one-fifth 
the whole lift. See Art. 19. 

(d) By making the lower part of the hoistway air-tight. 
See Art. 19. 

(r2) (ej) In case of fire, the shaft would act as a chimney 
and carry the fire from floor to floor. The closed shaft is 
always dark, and if windows are placed in the walls the 
danger from fire is increased. See Art. 20. 

(/O About 5 feet, or hi^h enough to prevent people bend- 
ing over the enclosure to look for the car. See Art. 20. 

( DJ) Elevator doors should be sliding doors or gates that 
operate freely. They should be so locked that they can 
only l)e opened from the inside of the shaft. Self-locking 
doors are preferable. See Art. !21. 

(11) P>y means of a car-locking device that prevents the 
ojxraiion of the startinji^ or operating device in the car 
while lh«! door is open. See Art. 2o, 

(!.')) I>y means of mechanically operated indicators that 
indi( ale the j)osition of the car and whether it is going up 
or (l..\vn. See Art. 29. 

(HI) h'or lliat (lass of service where the lift is short and 
wh'T'- j^rcat numbers of j)eople are to be carried. See 
Art. lill. 


(1) In the one-pipe system, but one line of pipe is used to 
connect the boiler and radiators. This necessitates return- 
ing the water of condensation to the boiler through the 
steam main. See Art. 17. 

(2) The manner of returning the water of condensation 
to the boiler. See Art. 16, 

(3) The circulation is uncertain, owing to the formation 
of slugs of water in the pipes; the steam is likely to be wet, 
as it is always in contact with the returning water; water 
hammer and sizzling noises are very liable to occur; in the 
case of large systems, the return of the water of condensa- 
tion through the steam pipes greatly interferes with the 
flow of steam to the radiators. See Arts. 21 and 23, 

(4) About i inch in 10 feet. See Art. 26. 

(5) By using vertical offsets or relays. See Art. 28. 

(6) (a) No. See Art. 30. 

(^) The expansion of the riser will either bend the main 
or raise the radiators connected to it. The weight of the 
riser will also tend to bend the main. See Art. 30. 

(7) If the steam valve is left slightly open, the steam 
will be condensed as fast as it enters the radiator; and as 
the opening is so small, little or no water will escape. See 
Art. 23. 

(8) If there is a slight difference in the pressure at the 
various radiators, the steam will flow backwards through the 



return pipes and interfere with the drainage or cause water 
hammer. See Art. 36, 

{^) Usinij rule 1, Art. 41, the diameter is found to be 

I Vi>V "^ .T854 = T.i>7 in., or 8 in. in practice. An& 

(10> Alvnit H inches per hundred feet. See Art. 43. 

(in Vsin^ rule a* Art. 42, we find the surface to be 
•V \ .:!i,U X UK> = •>,S:iT.4 sq. ft. Ans. 

^l:J) Ry a hydrv>siaiio test to detect any defective fittings 
or split pijvs, and by a steam test to see if expansion has 
Kvn prv^jvrly prv>Yivleil for and that the system is in work- 
iuij order. See Art, 53. 

{VM ^.r» By increasing the emitting surface, the heat is 
v^ivca v»tf more raindlv and with but little decrease in tem- 
^vrature ot the heat -transmitting surfaces. See Art. 75. 

V» N<»: the plain surfaces clear themselves more readily 
than the exte ruled surfaces and are. therefore, more eflFect- 
ivc. S«.v Art. #5. 

1 14 1 Tho air has tree a^vess to the tubes, and as it does 

T».»: vi^s VvT Vu: ^".j row . f tubes, each tube will operate 
u:.»' •* .'i • ' <:x:,ui'*v !uv :rj:r.:^erature. thus makinsj the rate 
v^: ^••rvo •■•': : hca: a :nav::r.v.m. See Art. 78. 

»:^» l'^.* :"^:j' : ::.' radiat«»r is well supplied with 

air ar.d : x* rV.:-.-^ a-: .i !r.:^h vel«vitv to the warmed air. 

which c-^'-i- ^ i-v;-. >i<trs : -. ; eriiciencv of the flue heat in ^r 
surtaoc-i. Svv;' A:: SlK 

(It'.i < n r ^J : :/ : .: vs w:'.'. be warmer than the bi.^ctom 
ones a"rd i>.is ;.'\ya'* i :r.-7\\ ^vhich will cause the pipetj t" 
bulge au! : X' :• : \fa.v See Art. 83. 

(^) A :Tt::o:" o.\". sh- /:.:'..: je used. See Art. 82. 

(17) r*v-* N-i>. r. :: 'e :< ^irnvly a tube capped at one 
end and d-vio* :: :.v yassa^t^s by a sheet -iron plate that 
extends iiearlv :^ the e::-.: c :rie tube. The lower end ot 


the tube is screwed directly into the radiator base. See 
Art. 86. 

(18) By enclosing the base so that the fresh air, as it 
enters, is compelled to pass between the hot tubes before 
escaping into the room. See Art. 91. 

(19) Because the steam pressure may back up the water 
of condensation into the radiator through the returns and 
flood the building. See Art. 99, 

(20) If a single large radiator were used, it would prob- 
ably be difficult to regulate the temperature during mild 
weather. By using two radiators, one being larger than the 
other, the small one may be used during mild weather, the 
large one during moderate cold weather, and both during 
severe weather. See Art. 96. 

(21) The amount of glass surface is 3^ X G X 3 = G3 square 
feet. The exposed wall surface reduced to a glass surface is 

10 (20 + 30) - ()3 ,^^ r . o^u . . 1 1- 

— ^^ — — = 43.7 square feet. The total coolmg sur- 
face is 63 + 43.7 = 106.7 square feet. By rule 3, Art. 94, 
the number of square feet of radiating surface required is 

^r^r^ ^ X 106.7 = 48.2 square feet, nearly. Adding 30 per 

cent, for air leakage, we have 48.2 + 48.2 X .30 = 62.7 square 
feet, and now allowing 25 per cent, to allow for exposure to 
winds, we have 62.7+ 62.7 X .25 = 78.37, say 78.4 square 
feet. Ans. See Arts. 95 and 96. 

(22) The radiator valve leaks. vSee Art. 99. 

(23) The air valve is probably choked or closed. See 
Art. 98. 

(24) As far as possible from the steam inlet so that the 
air vent will not close before all the air has escaped. See 
Art 70. 

(25) (a) The ordinary air vent allows water as well as 
air to escape. 


7 ^Lbnutr i iia^ :c 




-= iTr -J. 

is I-l!* 



Note.— All items in this index refer first to the section (see the Preface) and fhen 
to the page of the section. Thus, ''Annunciator 40 )&** means that annunciator will 
be found on page 25 of section 40. 

A. Sec. Page. 
Absorption and discharge of air 88 42 
** of vibration due to 
gearing in ele- 
vators 87 6 

Accessories, Elevator 87 18 

Elevator 40 16 

Accumulator S4 96 

Accumulators 80 86 

Actual discharge 86 4 

" liftofpump 64 2 

" work done by a pump.. 86 5 
Advantages of horizontal hy- 
draulic elevators 39 25 
** of piston eleva- 
tors 39 9 

'* of vacuum heat- 
ing system 41 29 

Air, Absorption and discharge 

of 89 42 

'* and water, Pumping a 

mixture of K 44 

chamber, Si/.e of delivery. 85 15 
chamber. Special form of 

suction 86 18 

chamber. Watching the... 35 86 

chambers 86 18 

chambers. Delivery 85 14 

chambers. Loss of air from 85 15 

chambers, Purpose of 85 18 

chambers. Purpose of suc- 
tion 86 17 

chambers. Suction 85 17 

chambers. Testing 35 41 

cushions 40 15 

discharge valves 35 27 

lift, Pohl6 84 03 

vents 41 31 

Sec. l*age. 

Air vents and traps 41 31 

Alleviator 85 17 

Alternating current, Electric 
elevators oper- 
ated by 88 46 

" current motor, 
Otis electric ele- 
vator with 88 48 

Annunciator 40 25 

Appliances, Elevator safety.... 40 16 

Apron 39 12 

Area, Mean effective 36 8 

Arrangement of heating sur- 
faces 41 35 

'* of pit pump 84 44 

** Steam-main 41 9 

Attachment, High-duty 34 7 

High-duty 84 25 

Automatic electric elevator, 

Otis 88 76 

electric elevator 
with No. 2 floor 

controller, Otis.... 88 

electric elevators... 88 
stopping and start- 
ing devices for 

pumps 39 

Auxiliary piping 85 

" valve 39 

Average duties of pumps 36 

B. Sec. 

Back-stop buttons 39 

Ball nut 88 

Ballast pumps 36 

Base sections 41 

Basket, Suction 85 










Sec, Page. 
Belt connected, belt - shifting 

electric elevators 88 1 

*' connected, belt - shifting, 
reversible-motor e 1 e c - 

trie elevator 88 2 

** elevators 87 27 

'* elevators. Construction of 

controlling devices of — 87 S9 
" elevators, Examples of.... 87 85 
" elevators,General descrip- 
tion of parts of. 87 20 

** eleVators, Motor safeties 

for 87 82 

'* elevators. Operation and 

maintenance of 87 88 

Bleeder... 41 2 

Blowing out the cylinder 85 32 

*' out the steam piping . 35 81 

Boiler-feed pumps 80 80 

'' main. Connection of .... 41 11 

Bolts, Foundation 85 20 

Bottom and top stop valve. In- 
dependent 30 18 

Box coil 41 40 

Brake 37 11 

" Dynamic 88 10 

" Governor-controlled 

safety drum 40 IS 

" Ordinary 88 16 

Bull engine, Cornish 84 42 

Hundy loop 41 41 

Bushing sheaves 30 45 

Butterfly valve 35 9 

Buttons, Back-stop 39 44 

" Limit-stop 39 44 

By- pass pipes 35 !25 

*' pass. Steam end 35 26 

" pass viilve 39 40 

" pass, Water-end 35 25 

" passes 35 25 

C. Sec. Page. 

Cable. Hand 39 44 

Cables, StretcliinK of 39 43 

" wire ropes and guides, 

Care of 37 25 

Calculations relatinj*;: to pumps 36 1 

Cameron valve motion 'M 10 

Car indicator. Mechanical . 40 iJS 

~* indicators and signals 40 'i^ 

" locking device 40 iil 

" operating switch JiH G'J 

•' safeties 40 1 

" safeties 37 IH 

" safeties and guides.Care of 40 13 

Sec. Page. 

Car safeties, H igh-speed 40 6 

** safeties, Purpose of 40 1 

** safeties. Slow-speed 40 1 

'' safety, Otis high-speed... 40 7 

*' safety, See high-speed 40 9 

*' Settling of 89 48 

** signals and indicators. 

Electric 40 27 

Care of car safeties and guides 40 18 
"*• of wire ropes, cabies, and 

guides 87 25 

Cars, Elevator 87 8 

Cataract cylinder 84 12 

Ceiling and floor flanges 41 23 

Center-packed pump 8§ 51 

** packed pump, Triple- 
expansion 94 56 

Centrifugal pumps 84 35 

pumps. 36 89 

Chamber, Settling 86 28 

Charging pipe 35 26 

Circulating pipe 89 11 

Circulation 41 7 

Clack valves 85 6 

*' valves 86 9 

Clamp, Pipe 85 41 

Classification of pumps 84 5 

** of steam-heating 

systems 41 8 

Clearance of piping 41 23 

Closed elevator system 39 40 

Closing down hydraulic eleva- 
tors 39 45 

Coal consumption. Duty based 

on .36 17 

Coil, Box 41 40 

" Continuous flat 41 38 

•' Cooling 41 30 

•' Manifold 41 39 

•' Miter 41 38 

Coils 41 2 

•' and radiators 41 85 

*' Size of pipe for 41 40 

Comparison of direct-acting 
and flywheel 

pumps 36 40 

" of 1 i f t ing and 

force pumps... 34 46 
" of steam-heating 

systems 41 7 

Com pen.Siiting cylinders 34 26 

Compound d o u b 1 e-p lunger 

pump 34 54 

pump 34 20 

Comi)ression -type elevators. 

Fast-service 80 27 



Compression type of hydrau- 
lic elevators 39 

Condition of water end when 

starting 85 

Connection of boiler main 41 

Connections, Radiator 41 

" Radiator 41 

Riser 41 

Riser 41 

Construction of controlling de- 
vices for belt 

elevators 87 

" of hand-power 

elevators 87 

" of pump plungers 8S 
'* of pump valves.. 85 
*' ofplunger ele- 
vators 89 

'* of steam elevators 87 

Continuous flat coil 41 

Control, Power 88 

" Power 87 

Controller 88 

'* Otis automatic elec- 

tric elevator with 

No. 2 floor 88 

*' Otis elevator with 

G. S. magnet 88 

'' Otis G. S. magnet . . 88 

* Otis No. 8 magnet.. 88 

Simple 88 

" Speed-regulating... 88 

Controllers 37 

Hand- wheel 37 

'* Lever 87 

Controlling devices. FJlevator.. 37 
*' devices for belt 
elevators, Con- 
struction of 87 

" valves.Packing the 89 

Cooling coil 41 

Corner-post elevators 87 

Cornish bull engine 84 

" double-seat valve 35 

" pumping engine 84 

Counterbalancing elevators. . . 37 

Counterweight 37 

" guides 37 

Counterweights 87 

Crane worm-geared steam ele- 
vator 37 

Cross 41 

" exhaust 34 

Crosshead, Elevator 37 

Cup leathers 35 

Cushions, Air 40 



























Cycloidal pump, Root's 84 

Cylinder, Blowing out the 85 

Cataract 84 

** Groaning noise in 

the 89 

Cylinders, Compensating 34 

D. Sec, 

Dash relief valves 34 

'' relief valves, Using the.. 85 

Deep-well pumps 86 

Defects in pumps 35 

Definition and division of steam 

pumps 84 

** of pumps 34 

Delivery air chamber, Size of.. 35 

*' air chambers 85 

'* end troubles 85 

'* pipe leaks 85 

" pipe. Waste 85 

*' pipes. Size of suction 

and 86 

piping 85 

** piping. Run of 85 

" piping. Valves in.... 85 

*' valve deck 35 

Description of elevators. Gen- 
eral 37 

" of parts of belt ele- 
vators, General. 37 

Design of pipe systems 41 

Details of heating systems 41 

" of piping 41 

'* of pump water ends... 35 

Detroit loop 41 

Differential elevator, Fraser . . 88 

*' pump 34 

** valve 89 

Direct-acting and flywheel 
pumps. Comparison 

of 36 

** acting elevators 39 

'^ acting steam pumps 31 

'* acting steam pumps for 

mine work 84 

*' acting steam pumps. 

Multiple-expansion... 84 
" air-pressure pump, Har- 
ris 31 

** connected belted elec- 
tric elevator 88 

" connected electric ele- 
vators 3« 

" indirect radiation 41 

" radiation 41 





















Discharge 86 

" Actual 86 

** and absorption of air 39 

*' Theoretical 86 

'* valves. Air 8R 

Disk valves 85 

Displacement 86 

" pumps 86 

'* pumps 81 

Disposal of drainage 41 

District heating system 41 

Division and definitionof steam 

pumps 84 

Doors, Elcvat«»r 40 

" Requirements of eleva- 
tor 40 

" Self-opening and self- 
closing elevator 40 

•' Trap 40 

Double-acting inside -packed 

plunger pump 84 

" deck elevator 89 

" plunger pump, Com- 
pound 34 

" plunger pump,Simple 34 
" power vertical hy- 
draulic elevator — 39 
*' seat and single-seat 

valves 85 

" seat valve, Cornish... 3r» 

Draft tube 35 

Drainage. Di.spo.sal of 41 

«»f pipe .systems 41 

of pumps. Provision 

for •>> 

Drip pipe 41 

Drop riser 41 

" system 41 

Drum brake, (lovernor-con- 

t rolled satety 10 

elevators, Sitle travel 

of ropes in 37 

'* Reversinv^ 38 

Safety I<» 

^ vpe of elevator 37 

Drv ret urn main 41 

'• vacuum i)unips '^i 

I Junibwaiters 37 

Duplex i)o\ver pumps 31 

pump, Piston -valve 

Wortliinuton 31 

J) u ni p, Sli»le valvi", 

Worlhiui^ton 31 

pumps 'i4 

l)Uinps 31 

" j)unips. Types of 31 
























Sec. Pits9, 
Duplex steam pumps, Settinf{ 

the valves of 35 4^ 

Duties of pumps. Average 86 f4 

Duty based on coal consump- 
tion 86 17 

** based on heat units sup- 
plied 86 19 

*' based on steam consump- 
tion 86 18 

'* based on volume or 

weight pumped 86 88 

*' of a pump, BxpressinsT 

the 86 fS 

" of steam pumps 86 16 

Dynamic brake 88 19 

B. Sec. Page. 

Eccentric reducer 41 91 

Eflfecti ve area. Mean 86 8 

Efficiency of radiators 41 85 

*^ of various types of 

pumps. 86 M 

Electric car signals and indi- 

cators 40 87 

" elevator , Belt-con- 
connected, belt- 
shifting, reversible- 
motor 88 8 

" elevator. Direct-con- 
nected belted 38 11 

" elevator, Otis auto- 
matic 38 76 

" elevator with alterna- 
ting-current motor, 

Otis 38 48 

'* elevator with No. 2 
floor controller, Otis 

automatic 38 82 

" elevators 38 1 

*' elevators. Automatic. 38 75 
'• elevators. Be 1 1 -con- 
nected, belt-shifting 38 1 
'• elevators, Direct-con- 
nected :J8 11 

'* elevators. Examples 

of 38 15 

" elevators, 1 n d i rec t- 

conueoted 3H 1 

" elevators operated by 

alti-rnating current. ;J8 4«» 

elevators. Otis :J8 ,S4 

ck-v:itors, See 38 27 

" clcv.-itors with mag- 

ne; c.»ntrol :JS 52 

" sinking pump 34 52 

Klektron uU-vators ;W 15 



Elementary system of mag^net 

control 88 

Elevator accessories 87 

" accessories 40 

'* Belt-connected, belt- 
shiftinjTi reversible- 
motor electric 88 

** cars 87 

'* controlling devices . . 87 
" Crane worm -geared 

steam 87 

*' crosshead 87 

" Direct-connected 

belted electric 88 

doors 40 

'* doors, Requirements 

of 40 

** doors, Self-opening 

and self-closing 40 

*' Double-deck 89 

** Double-power verti- 
cal hydraulic 80 

'* Drum type of 87 

** enclosures 40 

*' Eraser differential... 88 

*' guide shoes 87 

'* guides 87 

** installation. General 

arrangement of 89 

** operating devices 37 

** Otis automatic elec- 
tric 38 

'* Otis spur-gcnred 

steam 37 

** Otis vertical 39 

** Overbalanced 87 

" packing, Wright's.... 89 
** plants, Operation and 
maintenance of hy- 
draulic 89 

'* plants, Star ting up 

and running 89 

" platform 87 

" posts 37 

" pump-pressure regu- 
lator, Mason 89 

" safety appliances 40 

" Sprague-Pratt screw. 38 
" Sprague-Pratt verti- 
cal type 38 

" transmitting devices. 37 
'' with alternating-cur- 
rent motor, Otis 

electric 38 

" with G. S. magnet 

controller, Otis 88 

H. S. v.— 34 


Sec. Page. 

Elevator with No. 2 floor con- 



Otis automatic elec- 


trie. ... 




Elevators, Absorption of vibra- 

tion due to gearing 






Advantages of hori- 


zontal hydraulic. 





Advantages of pis- 






Autopiatic electric. 






Belt-connected, belt- 




shifting electric 





Closing down hy- 






Compression type of 






Construction of con- 


trolling devices of 






Construction of 







Const r uct ion of 







Construction of 










Counterbalancing .. 







Direct- connected 


















Examples of belt . . 





Examples of elec- 




Fast-service com- 








General description 







General description 


of parts of belt 






Horizontal hydrau- 




lic piston 










Indirect - connected 

• t 





Lubrication of 




Motor safeties for 





Motor safeties for 


4 4 


Operation and main- 




tenance t)f belt.... 





Sec. Page, 
Elevators, Operation and main- 
tenance of hand- 

power 87 S4 

** Operation and main- 
tenance of steam.. 87 54 
'* operated b y alter- 
nating current. 

Electric 88 46 

Otis electric 88 84 

** Packing horizontal 

hydraulic 89 49 

Piston 88 9 

Plunger 89 2 

*' Principal parts of... 87 1 

•' Pumps for 89 84 

See electric 88 87 

" Service of plunger.. 89 2 

•' Side-post 87 2 

Side travel of ropes 

indrum 37 8 

*^ Slack - cable safety 

for steam 37 54 

" Steam 87 43 

Tanks for 89 84 

'* Tension type of hy- 
draulic 89 25 

" Vertical hydraulic 

piston 89 9 

" with magnet control. 

Electric 88 58 

Enclosures, Elevator 40 16 

Engine, Cornish bull 34 42 

" Cornish pumping 34 40 

Engines, Flywheel pumping.. . 34 5J9 

Municipal pumping. . 3<l 39 

Equalizing lever 40 6 

Escalators 40 30 

Essential features of vacuum 

healing system 41 27 

Examples of belt elevators 37 35 

** of electric eleva- 
tors 38 15 

Exhaust and vacuxim heating 

systems 41 24 

Cross 34 23 

" heating system. Gen- 
eral arrangement 

of 41 24 

" heating system. Sa- 
ving efTecled by 41 24 

l'2xi>.iiision of pipies ... 41 9 

pieces 41 18 

Kxj^rcss i)innp, Riecller 34 70 

Kx|>rfssin>^ the duty <>f a 

l)uinp .% 23 

Kxtendc'.l hetiting surfaces 41 35 

P. Sec, Page, 

Past-service cooipression-type 

elevators 80 87 

Fire pumps 86 88 

Fittings, Special 41 81 

Flanges, Floor and ceiling 41 88 

Flat coil. Continuous 41 88 

Floor and ceiling flanges 41 88 

** controller, Otis auto- 
matic electric elevator 

with No. 8 88 88 

** magnets 88 

Flow in pipes. Velocity of 86 

Flue radiators 41 

Flywheel and direct-acting 
pumps. Compari- 
son of . 86 

** mine pump 84 

*' pumping engines. . 84 

Foot-valves 85 

Force pump 84 

'* pumps, Comparison of 

lifting and 84 

Forced-draft heaters 41 

" return system 41 

Forcing, Limit of height to. . . . 84 

Ford regulating valve 89 

" rheostat regulator 89 

Form of heating surfaces 41 

Foundation bolts 35 

" templet, Use of . . . 36 

Foundations for large pumps. . 35 

*^ for small pumps. 85 

" General consider- 

ations affecting 

pump 85 

^' Material for pump 35 

Pump 85 

Frazer differential elevator ... 38 

Freezing, Precautions against. 89 

a. Sec. 

Gauge, Water 39 

Gearing in elevators, Absorp- 
tion of vibration due to 87 

General arrangement of ele- 
vator installation... 39 
" arrangement of ex- 
haust heating sys- 
tem 41 

" considerations affect- 
ing pump founda- 
tions 35 

description of eleva- 
tors .. ., 37 1 

" description of parts of 

belt elevators 37 29 
















Sec. Page. 
General description of vacuum 

heatingr system 41 27 

** features of magnet 

control 88 

'* piping arrangement.. 85 

** service pumps 86 

Getting a pump ready.. 86 

'' up steam 86 

Girdle 40 

Governor-c o n t r o 1 1 e d safety 

drum brake 4<) 

" Pump 41 

Gordon steam pump 84 

Gravity-return system 41 

** wedge safety, Otis.... 40 

Groaning noise in the cylinder 80 

Guide shoes. Elevator 87 

Guides, Care of car safeties and 40 

** Counterweight 87 

*' Elevator 87 

** wire ropes and cables. 

Care of 87 

H. Sec. 

Hand cable 89 

Hand-power elevators 87 

" power elevators, Con- 
struction of 87 

'* power elevators. Oper- 
ation and maintenance 

of 87 

** wheel controllers 37 

*' wheel operating device 87 
Harris direct- air-pressure 

pump 34 ' 

Headers 41 

Heat units supplied, Duty 

based on 36 

Heaters, Forced-draft 41 

Heating by steam, Methods of 41 
" plant. Operating a... 41 
** Size of pipes for steam 41 
*' surfaces. Arrange- 
ment of 41 

'* surfaces, Extended.. 41 

" surfaces, Form of 41 

" surfaces. Plain 41 

" system. Advantage of 

vacuum 41 

" system details 41 

*' system. District 41 

" system, P^ssential fea- 
tures of vacuum 41 

" system, General ar- 
rangement of ex- 
haust 41 24 


















Sec. Page. 
Heating system. General de- 
scription of vacuum 41 27 
^' system, Saving effect- 
ed by exhaust 41 24 

system. Vacuum 41 27 

*' systems. Classifica- 
tion of steam 41 8 

** systems, Comparis<m 

of steam 41 7 

'* systems, Exhaust and 

vacuum 41 24 

*•*■ systems. Subdivision 

of large steam 41 8 

High-duty attachment 84 25 

*' duty attachment 34 7 

** speed car safeties 40 6 

" speed car safety, Otis 40 7 

"*" speed car safety. See 40 9 

Horizontal hydraulic eleva- 
tors, Advantages 

of 89 25 

" hydraulic eleva- 

tors, Packing... 89 49 
*' hydraulic piston 

elevators 89 25 

Horsepower of pumps. 86 6 

Hot water. Pumping 84 8 

How water flows into a pump. 84 1 
Hydraulic elevator. Double- 
power vertical.. 80 21 
*' elevator plants. 

Operation and 
maintenance of. 89 41 

" elevators 39 1 

"" elevators. Advan- 
tages of horizon- 
tal 30 25 

** elevators. Closing 

down 80 45 

" elevators. Com- 

pression type of. 89 25 
'* elevators. Packing 

horizontal 89 49 

" elevators. Tension 

type of 89 25 

elevators. Vertical 39 
" piston elevators. 

Horizontal 80 25 

I. Sec. Page. 

Idler 37 4 

Independent top and bottom 

stop valves 30 18 

Indicator, Mechanical car 40 25 

Indicators and signals. Car. ... 40 25 



Sec. Page. 
Indicators and sig^nals, Electric 

car 40 27 

Indirect-connected electric ele- 
vators 88 1 

^^ radiation 41 8 

Inside-packed plunger pump. 

Double-acting 84 65 

Installation, General arrange- 
ment of elevator 39 82 

Isochronal valve gear 34 11 

K. Sec. Page. 

Keying up 35 38 

Kno wles valve motion 31 8 

L. Sec. Page. 
Leakage of pistons and plung- 
ers 35 41 

*^ past pistons and 

plungers 35 42 

** Testing pumps for... 35 39 

Leaks, Delivery pipe 85 40 

*' past the valves 35 42 

Leaky pipes, Repairing 85 40 

Lever controllers 37 18 

" Equalizing 40 6 

" Otis 87 16 

Lift of pump, Actual 34 2 

" of pump, Theoretical 34 2 

Lifting and force pumps. Com- 
parison of. '^4 46 

" pump 34 47 

Light service pumps 3() .'J3 

Limit of height to forcing 34 3 

" stop buttons 3l» 44 

" stops 37 ;« 

" stops <m motors 37 33 

" stops on shipper rope .. . 37 32 
Locati<m of pump in respect to 

supply 35 'J-,* 

" of vacuum chambers 35 IW 

c»f valves 41 '^'6 

Loop, Rundy 41 41 

Detroit 41 41 

Loss of air from air chambers. 35 15 

Low-pressure steam pumps... Ii<t 33 

Lubricati<jn of elevators 3'J ^1 

M. See. /VfV- 
Magnet control, ICiectric eleva- 

IoTn with 3.S 5'2 

I- nil I r o 1, IClementary 

svstem of ,'J« r>3 

Sec. Page. 
Magnet control. General fea- 
tures of 88 58 

*' controller, Otis eleva- 
tor with G. S 88 57 

** controller, Otis G. S... 88 66 

*' controller, Otis No. 6.. 88 69 

Magnets, Floor 88 77 

Main, Connection of boiler.... 41 11 

Dry return 41 3 

*• Overhead 41 1 

** Return 41 8 

*' Rising 41 1 

" Steam 41 9 

** Steam 41 1 

" Wet return 41 2 

Mains, Size of steam 41 17 

Maintenance and oi>eration of 

belt elevators.. 87 89 
** and operation of 
hydraulic eleva- 
tor plants. 39 41 

*^ and operation of 

steam elevators 87 54 
** of hand-power 
elevators, Op- 
eration and.... 87 24 

Management of pumps 85 29 

Manifold coil 41 39 

Marsh steam pump 31 13 

*' valve motion 84 13 

Mason elevator pump-pressure 

regulator 39 3« 

Material for pump foundations 85 20 

Packing .30 51 

Mean effective area 30 3 

Mechanical car indicator 40 25 

Mechanically operated rheo- 
stats 38 3 

Method of procedure in piping 

a b.iilding 41 22 

Methods of heating by .steam.. 41 3 

Mine pump. Flywheel 3-1 .55 

*' pumps 34 3« 

" pumps 30 34 

*• pumps. Service of 34 .'O 

'* pumps. Types of 'W 44) 

" work, Direct- acting 

steam i)umi>s for 34 53 

.Miter coil ^1 3*< 

Mixture of water and air. 

Putnimivca 35 4( 

.Ml )t or safeties 3T 18 

safeties f(»r belt eleva- 
tors 37 3-» 

safeties for steam eleva- 
tors 37 50 



Sec. Page. 

Motors, Limit stops on 37 33 

Movinf? stairways 40 30 

MultipIe*expansion direct-act- 
ing steam pumps 34 90 

Municipal pumping engines ..36 39 

N. Sec. Page. 

Nnson tube 41 40 

Negative slip 3<J 4 

Noise in the cylinder, CiroaninK 39 43 

Non-circulating systems 3t) 22 

O. St'c. Page. 

Oiling ... 35 34 

One-pipe system 41 4 

Operating a heating plant 41 40 

'• device. Hand-wheel 87 16 

" device, Otis 37 16 

" devices, Elevator... 3r 11 
Operation and maintenance of 

belt elevators 87 89 

** and maintenance of 
hand-p<»wi.-r eleva- 
tors 87 24 

*'' and maintenance of 

hydraulic elevator 

plants 89 41 

** and maintenance of 

steam elevators. . . 37 54 

Ordinary brake 3« 16 

Otis automatic electric elevator 3S 76 
** automatic electric elevator 
with No. 2 tloor control- 
ler 8S K2 

** electric elevator with al- 
ternating-current mt)tor. 38 48 

" electric elevators 88 34 

•* elevator with G. S. magnet 

controller 88 57 

** gravity- wedge safety 40 5 

** high-speed car safety 40 7 

** lever 87 16 

" OS. magnet c«introller.... 38 58 

" No. magnet controller... 8S 69 

" operating device 87 16 

" spur-geared steam eleva- 
tor 87 43 

" vertical elevator 89 13 

Outside-packed pumps %\ 53 

Overbalanced elevator 37 7 

Overhead main 41 1 

P. Sec. Page. 
Packing horizontal hydraulic 

elevators 30 40 

** piston r«»ds 39 46 


Packing material 89 

" plunger 89 

'* Plunger 85 

** rods and stems 35 

** stufHngboxes 39 

'* the controlling 

valves 39 

** vertical cylinder 

pistons 39 

** Wright's elevator 39 

Parts of belt elevators. Gen- 
eral descripti<m of 37 

Pilot valves 89 

I'in radiator 41 

Pipe, Charging 85 

" Clamp 35 

" Drip 41 

** for coils, Size of 41 

*"* leaks. Delivery 85 

*' Priming 85 

" Relief 41 

•• Relief 41 

*' Runofsuction 85 

** Starting 85 

*' systems. Design of 41 

" systems. Drainage of — 41 

'* Testing the suction 85 

" Wa.ste delivery 35 

Pipes, By-pass 85 

" Exp.ansion »>f 41 

'* for .steam heating. Size 

of 41 

*' Repairing leaky 85 

** Surging of water in 85 

'* Velocity of flow in 85 

Piping 85 

** a building 41 

** a building. Method of 

procedure in 41 

'* arrangement, General. 85 

Auxiliary 35 

'* Blowing out the steam 35 

•* Clearance of 41 

" Delivery 84 

Details of 41 

** Run of delivery 85 

" Suction 86 

systems for steam dis- 
tribution 41 

Testing 41 

" Valves in delivery 85 

Piston elevators 39 

** elevators, Advantages 

of 39 

'• elevators, Horizimtal 

hydraulic 89 





















Sec. Page. 
Piston elevator*. Vertical hy- 
draulic 39 9 

rods Packing 39 4« 

** valve, Worthington du- 
plex pump 84 17 

Pistons and plungers, Leakage 

of 85 4t 

** and plungers, Leakage 

past 35 42 

*' and plungers. Size of.. 86 10 
*' Packing vertical cyl- 

der 89 48 

♦* Pump 85 5 

Pit-pump arrangement &t 44 

•* pumps 84 40 

** pumps. Water end of 84 46 

** work 81 40 

Plain heating surfaces 41 85 

Platform, Elevator 87 8 

Plunger, Construction of pump 85 1 

" elevators...^ 89 2 

'* elevators, Construc- 
tion of 89 2 

" elevators, Service of.. 39 2 

'' packing 85 2 

Packing 89 46 

'* pump, Double-acting 

inside-packed 84 65 

Plungers and pistons, I^eakage 

of &•> 41 

" and pistons, I>eakage 

past 35 42 

** and pistons. Size of, . 36 10 

Poljl^air lift 34 0.3 

Pole chatiK'cT as 13 

Posts, ICleviitor 37 2. 

Pot valves 85 12 

Potential switch 3^ 44 

Power control :iT 11 

control 38 13 

pumps 34 37 

" pumps 3<? 38 

" pumps. Duplex 34 37 

" pumps, Sinj;le 34 37 

pumps, Triplex 34 37 

Precautions aj^ainst freezinj^.. 39 45 

Pressure punii)s 36 34 

" lej^ulated St a r t i n X 

valve 39 liS 

Prim inj^ pipe , 35 iiO 

Principal i^arts of elevators — 37 1 

" risers, Size of 41 17 

Proportioning^ radiation sur- 
face 41 44 

Provision for drainajije of 

pumps .'iTj '^9 


Ptilsometer SI 

Pump, Actual lift of 84 

** Actual work done by a. 86 

Center-packed 84 

** Compound .*. 84 

" Compound double-plun- 
ger 84 

** Differential 84 

'* Double-acting inside- 
packed plunger 84 

''*' Electric sinking 84 

'* Expressing the duty of a 86 

*' Flywheel mine 84 

** Force 84 

** foundations 85 

*' foundations. General 
considerations affect- 
ing 85 

" f ou ndations. Material 

for 85 

** Gordon steam 84 

'* governor 41 

*' Harris direct- air-pres- 
sure 84 

*' How water flows into a 84 
in respect to supply. Lo- 
cation of 85 

•♦ Lifting 84 

'* management 35 

'* Marsh steam 34 

" Piston-valve Worthing- 

ton duplex 31 

pistons 85 

plungers. Construction 

of 35 

" pressure regulator, Ma- 
son elevator 39 

*' Quimby screw 34 

" ready, Getting a 85 

" Riedler express 84 

" Root's cycloidal 84 

" Scran Ion typ)e of 34 

Slide-valve Worthing- 

ton duplex 84 

" Simple double-plunger. 84 

*' Steam sinking 34 

Theoretical lift of 34 

Triple-expansion 84 

" Triple expansioncenter- 

packed 34 

" Useful work done by a. 36 

'* Vacuum 41 

valves,. • 'VJ 

" valves. Construction of. 35 

water ends. Details of.. 35 

*' Work done by a 36 






















Pampingr a mixture of water 

and air 85 

*' eugine, Cornish 84 

'• engines. Flywheel... 84 

'* engines, Municipal.. 86 

** hot water 84 

Pumps, Automatic stopping and 

starting devices for. .. 89 

** Average duties of 86 

** Ballast 36 

Boiler-feed 36 

**■ Calculations relating to 3C 

" Centrifugal 86 

" Centrifugal 84 

*• Classification of 84 

** Comparison of direct- 
acting and flywheel . . S(i 
" Comparison of lifting 

and force 34 

" Deep- well 86 

Defectsiin 85 

*^ Definition and division 

of steam 84 

Definition of 84 

Direct-acting steam 84 

** Displacement 86 

*' Displacement W 

" Dry vacuum 86 

Duplex 84 

Duplex 84 

'* Duplex power 84 

" Duty of steam 86 

'* Efficiency of various 

types of 86 

Fire 86 

" for elevators 89 

" for leakage, Testing.. . 85 

" Foundations for large.. 85 

*' Foundations for small.. 85 

" General service 86 

'* Horsepower of 86 

" Light service 86 

" Low-pressure steam.... 86 

Mine 84 

Mine 86 

'* Multiple-expansion 

direct-acting steam .. 34 

Outside-packed 81 

Pit 84 

Power 86 

Power 84 

*' Pressure 36 

*' Provision for drainage 

of 85 

* Reciprocating 36 

" Reciprocating 86 
















Sec. Page. 

Pumps, Riedler 34 70 

Rotary 86 29 

Rotary 84 88 

Screw 86 80 

Selection of 86 29 

" Service of different 

types of 86 29 

" Service of mine 84 89 

" Setting the valves of 

duplex steam 85 46 

Sewage 86 87 

Single power 34 37 

Sinking 86 86 

Sinking 34 50 

Starting 36 21 

Steam 34 5 

Tank 36 38 

*' Triplex power 84 37 

" Types of duplex 84 14 

*' Types of mine 84 40 

*' Vacuum 86 40 

Valve gear of Riedler. . 84 71 

" Valve motions of steam 84 8 

»* Water end of pit 84 46 

"^ Water ends of recipro- 
cating 34 64 

" Wet vacuum 86 40 

Wrecking 86 36 

Purpose of car safeties 40 1 

** of suction air cham- 
bers 5 17 

Q. Sec. Pajst 

Quimby screw pump 34 84 

R. Sec. Pafre. 

Radiation, Direct 41 2 

Direct-indirect 41 8 

Indirect 41 8 

" surface, Proportion- 
ing 41 44 

Radiator connections 41 2 

" connections 41 18 

" Pin 41 42 

Radiators and coils 41 35 

" Efficiency of 41 35 

" Flue 41 37 

Reciprocating pumps 36 29 

" pumps 86 80 

'* pumps, Water 

ends of 34 04 

Reducer, Eccentric 41 21 

Regulating valve. Ford 39 36 

Regulator, Ford rheostat 39 36 

" Mason elevator 

pump-pressure 30 38 



Sec. Page, 

Relays 41 11 

Relief pip>e 41 % 

'* pipe 41 6 

" valve 39 13 

" valves. Dash W 19 

Repairing leaky pipes 35 40 

Requirements of elevator 

doors 40 17 

Return main 41 9 

main. Dry 41 % 

main, Wet 41 8 

** risers 41 % 

" traps 41 33 

Returns 41 50 

Water level in 41 16 

Reversing drum 88 39 

" switch 38 13 

switch 38 4 

Rheostat regulatt>r. Ford 89 86 

Rheostats, Mechanically oper- 

uied 88 8 

Solenoid 38 10 

Riedler express pump 84 76 

pumps. 84 70 

•• pumps. Valve gear of. 34 71 

valve 84 71 

Riser connections 41 IS 

" connections 41 2 

*• l)ri>p 41 2 

Risers 41 1 

keiurn 41 2 

Si/.e of princip>al 41 17 

Hisinv:^ main 41 1 

R<»<ls aiiil sU'ins, Packing 3.") Ii3 

'' Shackle 40 6 

Root's ovcM'iilai pump .'14 33 

Rope. Limit stops on bhipper.. 37 32 

Sati'tv 4(> 12 

" Shipper 87 11 

" Take-up 40 12 

kdtaiy pumps 3'> 29 

•' pumi)s 34 32 

Kuti of delivery piping 34 24 

•' of suet '(.n pipe 35 22 

RunnM^v: aiiil starting up ele- 
vator jilants 39 41 

S. Sfc. Pdfi'e. 
Safetifs aii'l j^uides. Care of 

car 40 13 

C"ai 37 Iw 

Car 40 1 

Hi!.:li-s])i.-f(l tar 40 ft 

M..t..r 3: IS 

•' I\u pose of car to 1 

S!o\v -^pei'.l eai .... tO 1 

Sec. Page, 

Safety appliances. Elevator.. . 40 16 

devices 87 18 

" drum 40 19 

" drum brake, Governor- 
controlled 40 13 

" Otis high-speed car 40 7 

" Otis gravity- wedge 40 5 

" plank 40 5 

rope 40 12 

" See high-speed car.... 40 9 

Slack cable 87 34 

valve 89 41 

Saving effected by exhaust 

heating system 41 S4 

Scranton type of pump 84 55 

Screw elevator, Sprague-Pratt 88 86 

" pump, Quimby 84 31 

*' pumps 86 80 

See electric elevators. 88 S7 

** high-speed car safety 40 9 

Selection of pumps 86 89 

Self-opening and self-closing 

elevator doors 40 19 

Separate-return system 41 6 

Service of different types of 

pumps 36 S9 

'* of mine pumps 34 39 

*' of plunger elevators.. 30 3 
Setting the valves of duplex 

steam pumps 35 46 

Settling chamber 35 23 

of car 39 43 

Se wage pumps 3C 37 • 

Shackle 87 26 

rods 40 6 

Sheave, Shipper 37 12 

Traveling 39 10 

Sheaves, Hushing 3*.> 45 

Shipper rope 37 11 

'• rope, Limit stops on .. 37 32 

sheave 37 12 

Side post elcvator.s ;<? 2 

*' travel of ropes in drum 

elevators 37 8 

Signals and indicators, Car. .. . 40 25 
" and indicators, Klectric 

car 40 27 

Simple controller 31^ 15 

d<'Uble-plunger pump.. 34 :A 

Si n>^ie power pumps 31 37 

seat and double-seat 

valves a*) 10 

Sinking pump, Electric 34 52 

pump. Steam 31 .V» 

l)uinps 'M r.0 

pumps . 30 :w 



Strc. Page. 

Size of delivery air chamber.. 35 1ft 

" of pipe for coils 41 40 

** of pipes for steam heat- 
ing 41 16 

^* of pistons and plungers... 86 10 

" of principal risers 41 17 

*^ of steam end 36 18 

** of steam mains 41 17 

** of suction and delivery 

pipes 36 25 

*' of vacuum chambers 85 19 

Slack-cable safety 3? 34 

*' cable safety for steam 

elevators 37 54 

Slide-valve Worthington du- 
plex pump 34 15 

Slip 86 4 

** Negative 36 4 

Slow-speed car safeties 4U 1 

Solenoid rheostats 38 10 

Special fittings 41 21 

*' form of .suction air 

chamber 85 18 

Speed regulating controller 88 21 

Sprague-Pratt screw elevator. 88 86 
" Pratt vertical type 

elevator 38 91 

Spring piece 41 18 

piece 41 12 

Spur-geared steam elevator, 

Otis 37 43 

Stairways, Moving 40 .*10 

Starting and stopping devices 
for pumps, Auto- 
matic 39 35 

" Condition <»f water end 

when 85 35 

pipe 35 27 

pumps 35 31 

" up and running eleva- 
tor i>lants 3t) 41 

*• valve. Pressure-regu- 
lated 39 35 

Steam consumption. Duty 

based on.. 36 18 

" distribution. Piping .sys- 
tems for 41 4 

** elevator. Crane worm- 
geared 37 48 

'* elevator. Otis spur- 
geared 87 43 

" elevators 87 42 

" elevators. Construction 

of 37 42 

" elevators. Mot or safeties 

for 37 50 






Steam eIevators,Operation and 

maintenance of 37 

*' elevators. Slack-cable 

safety for 87 

** end ... 85 

*' end, Size of 86 

** end troubles 35 

*' Getting up 85 

•* heating 41 

** heating, Size of pipes 

for 41 

*^ heating systems, Classi- 

ficxition of 41 

*' heating systems, Com- 
parison of 41 

** heating system.s. Sub- 
division of large 41 

*' piping. Blowing out the 35 

" pump, Oord<m 'M 

*' pump. Marsh 34 

" pumps 84 

'* pumps. Definition and 

division of &1 

" pumps, Direct-acting.. 34 

'* pumps. Duty of 36 

" pumps for mine work. 

Direct-acting 34 

** punip.H, Low-pressure.. 86 
'* pum])s, Multiple-expan- 

sic>n direct-acting 31 

" pumps, .Setting the 

valves of duplex 35 

" pumps. Valve motions 

of 34 

" main 41 

** main 41 

*' main arrangement 41 

*' mains. Size of 41 

" Methods of heating by. 41 

" sinking pump 84 

Stems and rods. Packing 35 

Stop-motion switch 3S 

*' valve, Independent top 

and bottom 39 

Stopping and starting devices 

for pumps. Automatic 39 

Strainer, Suction 35 

Stretching of cables 39 

Stuffingboxes, Packing 39 

Subdivisicm of large steam- 
heating systems 41 

Suction air chamber. Special 

form of 35 

" air chambers 35 

•* air chambers, I*urpose 

of 35 17 






















Suction and delivery pipes, 

Size of 36 

" basket 36 

*' end troubles 85 

*' pipe, Run of 85 

** pipe. Testing the 85 

** piping 85 

*' strainer 35 

*' valve deck 85 

Surging of water in pipes 85 

Switch, Car-operating 88 

Potential 88 

" Reversing 88 

*' Reversing 88 

'* Stop-motion 88 

System, Closed elevator 89 

Systems, Non-circulating 89 

T. Sec. 

Take-up rope 40 

Tank pumps 86 

Tanks for elevators 89 

Templet, Use of foundation... 85 
Tension type of hydraulic 

elevators 89 

Testing air chambers 85 

" piping 41 

" pumps for leakage 85 

" the suction pipe 35 

Theoretical discliHrj^e 30 

" lift of pump 31 

Thimble 37 

Throttle 3Q 

Top and bottom stop vjilve, In- 
dependent 39 

Transmitiinf^ devices, Elevator 37 

Trapdoors 40 

Traps, Return 41 

Traveling shexi ve 30 

T r i p 1 e - e X p a n s i o n center- 
packed pump 34 

" expanftion pump 34 

Triplex in)wer pumps 3t 

Troubles, Delivery-end 35 

Steam-end a") 

Suction-end a") 

Tube, Nason 41 

T\vo-]iip(' system 41 

Typ<.'s «)f duplex pumps 34 

" of mint" pumps 'M 

" of pumps, Efticiency of 

various 3<> 

" i>f jninips. Service of ilif- 

ferent 3«» 

" water enils 31 















U. Sec. Page. 

Use of foundation templet 86 SI 

Useful work done by a pump.. 86 6 
Using the dash relief valves. . . 86 85 

V. Sec. Pagre. 
Vacuum and exhaust heating 

systems ^... 41 94 

*' chamber 86 18. 

** chambers. Location 

of 86 19 

" chambers, Sixe of 86 19 

" heating system 41 27 

" heating system. Ad- 
vantages of 41 t" 

** heating 8y8tem,Bssen- 

lial features of 41 W 

" heating system, Gen- i 

eral description of. . 41 |7 

'' pump 41 27 

** pumps 86 49 

" pumps. Dry 86 4r> 

*' pumps. Wet 86 40 

Valve, Auxiliary 89 18 

♦* Butterfly 85 .9 

»* By-pass 89 j40 

•» Clack 85 9 

** Cornish double-seat 85 11 

" deck 86 8 

'' deck, Delivery 35 9 

•' deck, Suction 85 9 

Differential 39 13 

Ford regulating 39 36 

" gear, Isochronal 34 11 

" gear of Riedler pumps. 34 71 

" motion, Cameron 34 10 

" motion, Know les 84 8 

motion. Marsh »4 13 

'* motions of steam pumps 34 8 
'* Pressure-regulated 

starting 89 85 

" Relief 89 18 

" Safety '■ ' 41 

Valves 8<» 41 

" Air discharge •'* • 27 

Clack S S 

C<mstructionof pump.. :i5 8 

Dash relief W 19 

Disk 85 8 

'* in delivery piping 35 24 

I^eaks past the 35 42 

" Location of 41 96 

" of duplex steam pumps, 

Setting' the 85 40 

Packinvr the controlling 39 51 

Pilot.. 39 13 



Sec. Page. 

Valves, Pot 85 12 

" Pump 35 7 

** Single-seat and double- 
seat 85 10 

'' Using the dash relief... 35 85 

Wing 85 12 

Velocity of flow in pipes 85 25 

Vents, Air 41 81 

Vertical cylinder pistons. Pack- 
ing 39 4« 

'* elevator, Otis 39 13 

'* hydraulic elevator. 

Double-power 89 21 

" hydraulic elevators... 89 9 
'* type elevator, 

Sprague- Pratt 88 91 

Vibration due to gearing in 

c'evators. Absorption of 87 6 

Vibrator 87 4 

Volume or weight pumped, 

Tiuty based on 86 28 

W. Sec. Page. 

Wa.Hte delivery pipe 85 27 

Waching the air chamber 35 86 

Water 84 1 

'* 89 41 

'* and air, Pumping a mix- 
ture of 85 44 

** end by -pass 35 25 

*' end of pit pumps 34 46 

Sec. Page. 
Water-end when starting. Con- 
dition of 85 35 

*' ends. Details of pump.. 85 1 
" ends of reciprocating 

pumps 84 64 

" ends. Types of 84 64 

"'' flows into a pump, How 84 1 

" gauge 89 40 

*' hamn>er ..41 7 

" hammer 85 18 

*' in pipes. Surging of 85 43 

" level in returns 41 16 

** Pumping hot 84 3 

" ram 89 18 

Weight or volume pumped. 

Duty based on 86 28 

Wet return main 41 2 

'* vacuum pumps 86 40 

Wing valves 85 12 

Wire ropes, cables, and guides, 

Care of 87 25 

Work done by a pump 36 5 

'^ done by a pump. Actual 86 5 

** done by a pump. Useful. 86 5 
Worm-geared steam elevator. 

Crane 87 48 

Worthington duplex pump. 

Piston- valve... 34 17 
** duplex pump, 

Slide-valve.... 84 15 

Wrecking pumps 86 36 

Wright's elevator packing 39 46